Atlantic directory, 1918

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* Chiefly from the United States Coast Survey Tide Tables, for the year 1892.

High Rise. High | Rise.

ee, Full and - Pull and Change. | Sps. } Nps. Change. Sps. | Nps, Pensacola, sccccocccess 2, Long Island ...... 8 30 4 34 WHOIS Sqaacoccnsonsan 2 ERMINE eoses oseseseece 7 20 24 Mississippi,S.W.Pass 13 Crooked Island ...... TO 23 San Juan, Porto : ; TRICE). Goo ceackoos sou Bae 1 Wiers Ortiz -oseccecn= 2-4 Virgin Islands, St. | Cape Catouche ...... 9 30 14 (Or Zatenedesseeecssers 30 4 Royal Harb., Ruatan| 7 45 34 Guadeloupe, Pointe Cape Gracias Harb.| 10 30 2 By JEAIGE= bop oaoqesoHan 10 0 1} Man of War Kay ... 8 10 2 Martinique, Fort Barbados, Carlisle > : BAN, (aseaeecarsoseces 3 0 3 1 West India Islands. | St. Lopes Kings- 2 Cuba, Havanua...... 8 14 3 GOW! osc cnseeeences a0 LAS) ok Bahia de Cadiz Grenada, St. George TEN ensasoaoaoocce 9 20 3 Ea DOUN eeceesscates 2 40 14 2. Port Baracoa...... 7 23 2 MODSSO) We eccescesccesses 3 0 4 2 Santiago de Cuba 8 30 2 Trinidad, Boca St. Domingo, Cape Gulf of Maracaibo 5 15 25

The following notes draw attention to peculiarities of the Tides as met with in various regions of the North Atlantic Ocean, of which more full and detailed accounts will be found in the Sailing Directions which accom- pany the Charts of the various coasts.

(1.) River Thames. - During strong North-Westerly gales, the Tide marks high water earlier in the River Thames than otherwise, and does not give so much water, whilst the ebb tide runs out later, and marks lower; but, upon the gales abating and the weather moderating, the Tides put in and rise much higher, whilst they also run longer before high water is marked, and with more velocity of current, nor do they run out so long or so low.

(2.) English Channel. - The Tides of the English Channel were but im- perfectly understood till Rear-Admiral Beechey, R.N., investigated a mass of observations which had been made about the year 1847, and which demonstrated that there was a great resemblance in the characteristics of the tidal phenomena of the English and Irish Channels, and this investi- gation led to a more extensive series of observations throughout the English Channel, which were also discussed by Admiral Beechey. From his valuable contribution to science and the mariner, in the '' Philosophical Transactions" for 1848 and 1851, we make the following extract : -

Instead of the progressive changes of stream turning progressively later as the Tide advances up the strait, they cease at a certain point, which is, in the English Channel, between the Start and Gulf of St. Malo; and in the North Sea, between the Texel and the Estuary of Lynn. Between these spots there is a Tide peculiar to the Channel, quite distinct from that of the seas on either side of it, which are always running in contrary

When these streams meet, the Tide is ever varying in its direction, according as the strength of one stream prevails over that of the other, giving to the water a rotary motion, with scarcely an interval of slack water; in the space between them the Tide sets steadily towards Dover, while the water is rising there, and away from it while it is falling at that place. This ''trwe Channel Stream"' is about 180 miles in extent in either direction, from the point of union of the Tides in the Strait of Dover to the region of rotatory Tides off Lynn, and off the Start and St. Malo.

As the true Channel Streams are always running in opposite courses, there is necessarily a point where they meet and separate, and this occurs in the Strait of Dover. But im this strait, the stream, although it first obeys one tide and then another, does not slack with the Channel Streams, but is found to be still running at high and low water on the shore, at which times those streams are at rest, so that the Strait of Dover never has slack water throughout its whole extent at any time. I have, in con- quence, called this an intermediate tide.

The limits of neither of the streams appear to be stationary, but range to and fro as the tide rises and falls at Dover, travelling to the Hastward on both sides, and at high and low water suddenly shifting 60 miles to the Westward to recommence their Easterly course with the next tide; and, although so far apart, they possess the remarkable peculiarity of shifting together ; so that the Channel Streams preserve, as nearly as possible, the same relative dimensions.

In the Strait of Dover, this line of meeting and of separation oscillates between Beachy Head and the North Foreland, a distance of about 60 miles. When the water on the shore at Dover begins to fall, a separation of the Channel Streams begins off Beachy Head. As the fall continues, this line creeps to the Eastward ; at two hours after high water it has reached Hastings ; at three hours, Rye ; and thus it travels on, until at low water by the shore it has arrived nearly at the North Foreland on one side of the strait, and at Dunkirk on the other. At this time the Channel Streams on both sides slack, but in that portion which I call the inter- mediate stream, in the Strait of Dover, the water is still running to the

Westward ; and when the new Channel Streams make, as the water rises on the shore, this intermediate portion is found to unite with, or to oppose, one or the other of these streams, according as it was before the reverse ; so that, as before mentioned, the line of meeting at low water appears off Beachy Head to recommence its Hasterly course. This intermediate stream forms a remarkable feature in the tidal system of the Channel; it is well established, as the line of meeting and of separation occupies a very limited space, and it seems to be entirely due to the contracted form of the Channel in this immediate locality preventing the free escape of the water.

Admiral W. Bullock, in order to test the point of separation, anchored two vessels a mile apart, between Beachy Head and Dungeness, and found both vessels at the same time to ride with their heads in opposite directions in obedience to the streams, which were then running opposite ways.

The Channel Stream, which I have described as running between the intermediate stream and the rotatory or mixed streams at the outer ex- tremities of the Channel, pursues a steady course along the main trunk of the strait, slacking only towards high and low water at Dover, when it is pre- paring to invert its course; and, contrary to the generally received opinion of a progressive slack water in a strait having a progressive establishment, this stream has the peculiarity of slacking throughout its whole extent at nearly the same time; and this time, as was anticipated in my former paper ('' Phil. Trans.," 1848), corresponds nearly with the time of high and low water on the shore at Dover, the site of the combined wave, and the virtual head of the tide.

A simple rule thus su'lices to guide the sailor up the main Channel Stream. It is, that the stream runs toward Dover while the water is rising there, and away from it while falling. The tidal hours for Dover, there- fore, answer for the whole of the Channel.

The meeting of the stream off the Casquets and the Start in the English Channel, and the direction there given to the water at a particular time of the tide, will fully answer for the numerous wrecks about the Channel Islands ; whilst near the Strait of Dover, an unexpected set of the stream directly down upon the Somme, and in a part of the Channel where, from its narrowness, a true stream might be expected, is evidence of the danger of approaching this part of the Channel, if ignorant of the set of the stream. And, most singularly, this occurs exactly in the spot where those disastrous wrecks of the Conqueror and Reliance took place, and where the Cwragoa, one of H.M. frigates, so narrowly escaped a similar fate.

Further particulars on the Tides of the English Channel will be found in the Sailing Directions accompanying the Chart.

(3.) Southampton, &c. - This port has the singular advantage of having two high waters, which adds not a little to its dock facilities. The same phenomenon is also found in other places within the Isle of Wight, and is owing to the Channel Tide passing round either end of the Isle of Wight, and arriving at the port at different times.

It will be observed that at Poole the rise and fall is insignificant, while on the opposite side of the Channel we have the gigantic tides of the Bay of St. Malo, a similar feature to that which is found in the Bristol

(4.) Bristol Channel. - The Tides of the Bristol Channel are remarkable for their magnitude and rapidity. There are few places in the world where they are exceeded. The Bay of Fundy, Nova Scotia, and the Bay of Mont St. Michel, on the French coast, are somewhat analogous. The effect of these rushing waters is to alter the channels and shift the banks in the upper portion of the Bristol Channel in a most extraordinary manner. Some idea is given in our Sailing Directions for the Bristol Channel.

Outside the Bristol Channel, spring tides rise from 22 to 24 and 26 feet; but as that channel narrows, or contracts in its breadth, the velocity and vertical rise increase in proportion ; and so much that, in King Road, it rises to the height of 40 feet and upwards.* Between Nash Point and Bridgewater Bay, past Hurlstone Point, &c., the Tide sets with great velocity over the Culver Sand, into Bridgewater Bay and River. Through Caldy Sound, the stream from Caermarthen Bay makes Westward nearly two hours before the flood has done running without the island; and the stream makes Hastward through the sound, as well as between the Hel- wick Sand and Worm's Head, nearly two hours before the Channel ebb

At Lundy Island, ordinary spring tides rise 27 feet, equinoctial springs 31 feet, and neaps 13 feet. In Barnstaple Bay, ordinary springs rise 25 feet, equinoctial 28 feet, and neaps 15 feet. In this bay, at from 2 to 3 miles from shore, a gentle stream sets to the Eastward, from the time of low water to four hours flood, and then to the Westward until low water again. In mid-channel, between this bay and Lundy Island, the streams of flood and ebb set tide and tide each way, according to the time of flowing on the shore, at the rate of 3 miles an hour on springs and 2 miles upon the neaps, allowing half an hour for slacking and veering out.

It should be understood that, within the range of Swansea Bay and its offing, at about 5 miles West of the Scarweathers, the first-quarter flood sets directly toward them; after which, and until half-flood, it sweeps 1 mile outside, nearing the West end of the Nash Sands; and ultimately setting, till high water, 8.S.E. by compass, which points well outside of all. It averages a rate of 4.and 5 knots on springs,.and 3 knots upon neaps, and changes exactly at the same time that it ceases to rise on the shore ; but slack water always lasts half an hour.

It has been observed that, over the shoals, and through the different channels, the velocity of the tides is greatly increased, and there is reason for believing that on springs the rate is nearly 6 knots.

There is always a strong tide under these shoals, which is, of course, increased or decreased according to the vertical rise. This is of consequence when working up near them, as some advantage may, in the daytime, be taken of it, by keeping on the proper side. Its influence will be manifest to any vessel thus situated, as she would nearly make her course good

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* Captain Andrew Livingston, ef Liverpool, to whom our eailier editions of this work were much indebted for many valuable and useful communications, informed us that he actually measured fully 50 feet rise of water, in November, 1813, at King Road, in a spring tide, At Chepstow, above, on the opposite side, the vertical rise of a spring

tide also averages 50 feet, not uncommonly attaining 60 feet, and has even been known to reach 72 feet.

when under their lee, but be swept away furiously on opening the different passages. Should it be desirable to have the true tide, it will therefore be requisite to keep on the North or South side of all the shoals, according to the ebb or flood.

(5.) St. George's Channel. - Much that has been said of the English Channel Tides is applicable to those of the St. George's Channel, a full description of which is given in the Sailing Directions accompanying the

In the St. George's or Irish Channel, experiments have shown that, not- withstanding the variety of times of high water throughout the channel, ihe turn of the stream over all that part which may be called the fair navigable portion of the channel is nearly simultaneous; that the Northern and Southern streams in both channels commence and end in all parts (practically speaking) at nearly the same time; and that time happens to correspond nearly with the time of high and low water on the shore at the entrance of Liverpool and of Morecambe Bay, a spot remarkable as being the point where the opposite tides, coming round the extremities of Ireland, terminate. So that it is necessary only to know the times of high and low water at either of these places to determine the hour when the stream of either tide wll commence or terninate in any part of the channel. For this purpose the Liverpool Tide Table may be used, subtracting 18 minutes from the times there given, in consequence of the George Pier being later in its high water than the point which is considered the head of the Tide.

The Tide from the Atlantic enters the St. George's Channel by two channels; of which Carnsore Point, the S.E. point of Ireland, and St. David's Head, the S.E. point of Wales, are the limits of the Southern one; and Rathlin and the Mull of Cantyre the boundaries of the Northern.

The central portion of the stream of flood or ingoing stream, runs nearly in a line from a point midway between the Tuskar and the Bishops, to a position 16 miles due West of Holyhead; beyond which it begins to expand Eastward and Westward; but its main body preserves its direction straight forward towards the Calf of Man and on towards Maughold Head. Here it is arrested by the flood or Southern stream from the North Channel coming 1ound the Point of Ayr, and is first turned round to the Eastward by it, 3nd then goes on with it at an easy rate direct from Morecambe Bay; thus shanging its direction nearly eight points.

The outer portions of the stream are necessarily deflected from the course of the great body of the water by the impediments of the banks on the Irish side of the channel, and by the tortuous form of the coast on the Welsh side. The Eastern portion rushes with great rapidity between the Smalls, Grassholm, and Milford Haven towards the Bishops, which it passes at a rate of between 4 and 5 knots; sets sharply round those rocks in an E.N.E. direction, right over the Bass Bank, and into Cardigan Bay; makes the circuit of that bay, and sets out again towards Bardsey, at the other extremity of it; the streams still continuing outside towards the South Stack, which it rounds, setting towards the Skerries at a rate of upwards of 4 knots; and, finally, turns sharp round those rocks for Liyver- pool and Morecambe Bay; completing on its way the high water in the Menai, and filling the Dee, the Mersey, and the Ribble.

(6.) The Western portion of the stream, after passing the Saltees, runs nearly in the direction of the Tuskar, sets sharply round it, and then takes a N.E. 4 N. direction, setting fairly along the coast, but over the banks skirting the shore; so that vessels tacking near the inner edge of the sands on the flood, and on the outer edge on the ebb, have been carried upon them and lost, especially upon the Arklow and Codling Banks. Abreast of the Arklow is situated that remarkable spot in the Irish Channel, where the tide scarcely rises or falls. The stream, notwithstanding, sweeps past it at the rate of 4 knots at the springs, and reaches the parallel of Wicklow Head. Here it encounters an extensive projection of the Codling Bank ; and while the outer portion takes the circuit of the bank, the inner stream sweeps over it, occasioning an overfall and strong rippling all round the edge, by which the bank may generally be discovered. Beyond this point the streams unite and flow on towards Howth and Lambay, growing gra- dually weaker as they proceed, until they ultimately expend themselves in a large space of still water situated between the Isle of Man and Car- lingford. There we have not been able to detect any stream; for there another remarkable phenomenon occurs - the water rising and falling, without having any perceptible stream. This space of still water is marked by a bottom of blue mud. Such is the course of the flowing water at the Southern Channel.

In the North Channel, the stream enters between the Mull of Cantyre and Rathlin Island simultaneously with that passing the Tuskar into the Southern Channel, but flows in the contrary direction. It runs at the rate of 3 knots at the springs, increasing to 5 knots near the Mull, and to 4 knots near Tor Point, on the opposite side of the channel. The main body sweeps to the S. by E., taking nearly the general direction of the channel, but pressing more heavily on the Wigtonshire coast.

The central portion, midway between the Mull of Galloway and the Copeland Islands, presses on towards the Northern half of the Isle of Man; and while one portion of it flows towards the Point of Ayre, the other makes for Contrary Head, and is there turned back to the N.E. nearly at a right angle to its early course. Passing Jurby Point, it re-unites with the other portion of the stream, and they jointly rush with a rapidity of from 4 to 5 knots round the Point of Ayre, and directly across all the banks lying off there, and catching up the stream from the South Channel off Maughold Head, they hurry on together towards that great point of union, Morecambe Bay. This bay, the grand receptacle of the streams from both channels, is notorious for its huge banks of sand, and also remarkable for a deep channel scoured out by the stream, and known as the Lune Deep, which is the great haven to all vessels bound to Fleet-

Such is a general description of the streams in the Irish Channel, which are produced by the flowing of the water, or which, for the purpose of distinction, we may designate the ingoing streams.

The ebbing, or outgoing streams, do not materially differ from the reverse of those, except that in the Southern Channel they press rather more over towards the Irish coast.

(7.) Havre. - Here high water remains stationary for 1®, and only rises or falls 13 inches for the space of 3", much facilitating the use of the docks.

(8.) Bay of Biscay. - On the coasts of the Bay, the tidal wave advancing from the Westward, makes high water almost at the same hour all around its shores ; and the range also does not vary greatly.

(9.) Strait of Gibraltar - In the middle of the Strait of Gibraltar, the surface current mostly and generally sets to the Hast; but on each side the flood tide sets to the Westward. On the European side, West of the Isle of Tarifa, it is high water at eleven oclock, but the stream without con- tinues to run until two o'clock. On the opposite shore of Africa, it is high water at ten o'clock, and the stream continues to run until one o'clock ; after which periods it changes on either side, and runs Eastward with the general current. Near the shores are many changes, counter-currents, and whirlpools, caused by, and varying with, the winds.*

(10.) West Coast of Africa. - The currents on the African coast (hereafter explained) render the given times of high water uncertain.

Between Cape Cantin and Cape Blanco they are strong, and set as shown on the chart.

In the road oft the Senegal, the current sets chiefly to the S.W. From the bar, strong freshes come down after the rains, and a powerful current of fresh water sets from the river to some distance out to sea.

In the Bay of Yof, to the N.E. of Cape Verde, the currents set rapidly, and sometimes in very dangerous whirls.

At the mouth of the Gambia, the greatest rise in the dry season is not more than 6 feet. Here the tide continues to run on the surface for an hour and a half after it ceases flowing on the shore.

The level of the sea, in the vicinity of Cape Coast Castle, is higher, by at least 6 feet, in the rainy season (which is the season of the strong 5. W. and Southerly winds, between April and September), than in the more serene weather of the dry season.

In the rainy season, or S.W. Monsoon, trunks of trees are frequently carried on shore, and found at 6 or 8 feet above the level of the sea in the dry season. In the rainy season, also, the tides ebb and flow regularly in the several rivers; but, in the dry season, the same rivers run ebb con- stantly, the level of the sea being then too low to allow the tide-waters to enter their mouths.

(11.) Newfoundland. - On the coasts of Newfoundland the Tides are very irregular, being greatly influenced by the prevailing wind. On all the Eastern coast they have nearly the same rise; springs about 6 feet, neaps 4 feet. At the entrance of St. John's they set-in in a bore.

Between Cape La Hune and Cape Ray the flood sets to the Westward in the offing very irregularly, but generally two or three hours after high water on shore. See more particularly our '' British American Navigator,"

* Commander Gorringe, U.S.N., when examining the bank he discovered in 1876, lying 130 miles West of Cape St. Vincent, found the Tides setting regularly N.E. and S.W., at the rate of 14 mile an hour. When examined by the officers of H.M.S. Salamis, in March, 1877, they were found to be the same.

in which also will be found a full account of the Tides of the River St. Lawrence, &c., of which a condensed account follows.

(12.) River St. Lawrence. - The flood tide, entering the River St. Law- cence, proceeds upwards in the wide and deep channel of the estuary, till it is obstructed by the contracted breadth of the river near Red Island, and the sudden shallowing of it near this part; from this cause it is prevented from continuing in its upward course, and in consequence of the quantity of water here collected not finding a sufficient outlet, it is reverted, and forms an eddy-flood. The stream of flood, therefore, runs in opposite direc- tions, on either side of the river. This stream coming from the Eastward, as it approaches the Northern part of Red Island Bank, runs very strong, sometimes at a rate of 4 knots, bearing round at this part, and proceeding in a different direction towards Razade Islands, with a velocity of from 2 to 3 miles per hour, and then proceeds onward with a constant current downwards, thus adding to the current of water from the river itself, and increasing its strength. It is strongest inshore, and extends about half- way over, diminishing in strength towards the middle; and from this difference in its velocity, and the unequal depth of the river, occasioning those violent whirls and ripples which occur in its strongest parts.

On the South coasts of that part of the river between Cape Gaspé and Green Island, there is no upward current from the tides that is available for navigation; during the floods at spring tides, there is a Westerly current felt close inshore, the line between the two streams being marked by strong rippling.

Off Point de Monts there is very little or no stream of flood, excepting close inshore, and the downward current is constant off that point. The point diverts the current to the §.5.E., which runs at arate of from 1 to 2 miles an hour, so that it is difficult for a vessel to beat round it with a Westerly wind.

During the ebb tide the stream runs down on both sides, strongest on the South, and weakest in the middle of the estuary. On the North shore it is turned to the Southward by the projecting points at the Bay de Mille Vaches, Port Bersimis, the Peninsula of Manicougan, and Point de Monts; this fact is important, and ought to be attended to, as this Southern ten- dency is increased at these points, by the water brought down by the large rivers between them.

On the South side the stream of the ebb tide is also increased, by the efflux of water from the Saguenay River, which, setting with great velocity across the tail of Red Island Bank, adds to the downward course of the

At 9 miles below Tadousac, or the Saguenay, is the eddy of the flood, and the stream on the surface always sets thence downward. Off Tadousac, the tide ebbs six hours eight minutes. Both streams here run three- quarters of an hour after high water. At Green Island it ebbs six hours twenty-four minutes, and flows six hours.

At the Isle aux Coudres it ebbs six hours twenty minutes, and flows six hours. Here the ebb stream continues an hour and a quarter after low water, and the flood three-quarters of an hour after high water. Within the Pillars, off St. Jean, the tide ebbs six hours fifty minutes, and flows

five hours twenty-five minutes. Both streams continue to run an hour after high and low water by the shore, but they are influenced in duration by strong winds.

At the Isle of Orleans the stream ebbs seven hours, and flows five hours twenty minutes. At Quebec it flows four hours forty-five minutes only, but the ebb runs seven hours and forty minutes.

From Green Island to Quebec the Tides rise irregularly, but very con siderably. From Coudre to Quebec the water falls 4 feet before the tide makes down. At the Isle of Coudre, in spring tides, the ebb runs at the rate of 2 knots; in extraordinary high tides, assisted by winds, the ebb has here been known to run quite 7 knots, and the flood 6 knots. Between Apple and Basque Isles, the ebb of the River Saguenay uniting here, it runs full 7 knots in the spring tides; yet, although the ebb is so strong, the flood is scarcely perceptible; and below the Isle of Bic there is no appearance of a flood tide.

(13.) Bay of Fundy. - Off Cape Sable the Tide runs at the rate of 3, and sometimes 4 miles an hour; and in the Bay of Fundy the Tides are very rapid, but uncertain both in velocity and direction. Cape d'Or and Cape Chignecto are high lands, with very steep cliffs and deep water close under them. The same kind of shore continues to the head of Chignecto Bay, where very extensive flats of mud and quicksands are left to dry at low water. Here the Tides come in a bore, rushing in with great rapidity ; they are known to flow at the Equinoxes from 60 to 70 feet perpendicular; and it is remarkable that, at the same time, they rise in the Bay Verte, on the Northern side of the isthmus, only 8 feet.

(14.) Mount Desert Rock. - At Mount Desert Rock the stream of flood divides to run Eastward and Westward. With the Skuttock Hills about N.N.E., and within 12 or 15 miles of those of Mount Desert, the flood stream sets E.N.E., and the ebb W.S.W.; but, at the distance of 27 or 30 miles from the land, the current, in general, sets to the 8.W. and more Westward. From Mount Desert Rock to the Fox Islands, at the entrance of the Bay of Penobscot, the flood stream sets W.S.W. along shore; but it nevertheless runs up to the Northward into Isle Haute Bay, &c.

(15.) Nantucket, &c. - Off this island and its vicinity is that remarkable but dangerous collection of shoals, which are so well known to all who navigate these waters. Their form and situation, and also the peculiarities of the Cape Cod Peninsula, lead to the inference that these characteristics are owing to some singular effect of the Tides and Currents. This subject has been partially investigated by the United States Coast Survey.

'The region about Nantucket and Martha's Vineyard is the dividing space between the cotidal hours of xii. and xv., and in this locality the combination of two apparently distinct tide-waves is observed. This com- bination presents the most singular forms, giving at times four high tides - in one day near the junction of Nantucket and Martha's Vineyard Sounds, and distorting the tide-wave generally, not only in these sounds, but also on the open sea-coast of Nantucket and Martha's Vineyard and Islands, and in Muskeget Channel. The great disturbance of the ocean level thus produced gives rise to those remarkable currents so peculiar to this neigh-

b ourhood, and so disastrous to commerce."

(16.) Florida, &c. - Near Kay West, on the Florida Reef, the Tides are, in some measure, regular within the reef; the flood setting to the West- ward, and the ebb contrary. To the Westward, between the Tortugas and Cayo Marques, the flood sets variably through to the Northward, and the ebb to the E.S.H.

It is remarkable that, on the South side of these kays, the flood comes from the South-Hastward; but on the North side of them, all the way from Kay West, the flood runs to the Hastward, along the edge of the bank, and to the Southward, through the little channels, in order to fill up the intermediate bays and lagoons, with the assistance of the flood from the Southward.

Westward of Kay West there is a general current to the South-West- ward, along the reef, and to some distance to the South side of it.

In Chatham Bay it runs tide and half-tide ; viz., three hours flood, then three hours ebb ; next nine hours flood, &. Here, in some places, it is a mere fall; but in some of the channels it is as much as four men can do to stem the current with a boat.

During a S.E. gale or storm, the water in the bays and rivers of West Florida has been known to rise 7 feet perpendicular, and vessels of burden _ have been driven in among the pine trees, at some distance from shore.

From Cape Roman, Northward and Westward, the tide seems to ebb and flow only once in the twenty-four hours; but it is irregular, and much governed by the winds. Yet the effects in a dry season are very perceptible in the rivers at a distance from the sea.

(17.) Bahamas, &c. - Although at the Bahamas the rise and fall are inconsiderable, the tide of flood sets an indraught on the Northern part of the Little Bahama Bank from every point of the compass, which renders an approach very dangerous. The tide sets with some force directly on and off the Western side of the Grand Bank of Bahama, particularly at the full and change of the moon. It is high water at half-past seven or thereabout, and the rise is 3 or 4 feet. On the Middle Ground of this bank the tides set in every direction.

In Providence N.W. Channel the current runs generally to the Eastward, about 2 miles an hour.

Near Egg Island, to the N.W. of Eleuthera, it is, however, uncertain, and great attention should be paid to the lead. In the passage within ligg Island the tide runs at the rate of 4 miles, and rises about 4 feet, the flood setting Eastward, and strongly over the reefs.

About the Berry Islands and Providence the water rises 2 feet higher when the sun comes to the Northward of the Line, than it does when the sun is to the Southward, and its strength is in a similar proportion. Here and at the Bemini Isles the flood sets to the N.H.

(286.) General Remarks. - A Current is to be understood as a stream on, or a particular set in the direction of, the surface of the sea, occa- sioned by Winds and other impulses, exclusive of (but which may be influenced by) the causes of the Tides. It is an observation of Dampier, that Currents are scarcely ever felt but at sea, and Tides only upon the coasts ; and it certainly is an established fact that Currents prevail mostly in those parts where the Tides are weak and scarcely perceptible, or where the sea, apparently little influenced by the causes of the Tides, is disposed to a quiescent state. This will be obvious by an attentive consideration of the following descriptions. The necessity of attention to the silent, imperceptible, and therefore dangerous operation of Currents, will be equally apparent.

(237.) The usual method of estimating the existence, direction, and velocity of a Current, is the comparison between the observed position of a ship and that obtained by dead-reckoning. It may be as well to observe in the outset, that this method of observation involves some amount of fallacy, as a Current will be the general receiver of all errors or imper- fections of observation, and beyond doubt the strength of Currents hag been frequently exaggerated from this very cause. Now, as the latitude is attained far more easily and accurately than the longitude, it follows that this exaggeration has been chiefly shown in those Currents supposed to move to East and West. Still, by combining a large number of obser- vations, we may safely conclude that they will neutralize each other's errors, and afford something like an accurate conclusion.

(238.) An excellent repository of a vast number of early Current obser- vations is found in the elaborate charts of Major Rennell, a great mine for facts in surface Current theory. Commander Maury's charts, and the more recent ones of our own and other Meteorological Offices, likewise afford a great addition to our stock of knowledge. This is also increased by numerous detached observations scattered through many works. All these, as far as attainable, were integrated at a great expenditure of labour, in the Chart of the North Atlantic Ocean, published by Mr. Laurie, which this work particularly elucidates.

(239.) But since that chart was constructed, a much more extensive series of observations has been incorporated with those just named, in a set of charts, one for each month of the year, published by the Meteorolo- gical Office in 1872. They were contained in the first 800 registers col- lected by that office, and were reduced by Mr. R. Strachan. In addition to these registers, the whole of the available data in Rennell's and Maury's charts were integrated with them, and thus gave a far more perfect view of the Atlantic Currents, between the Equator and 40° N., and from the African coast to the Gulf of Mexico, than was before attainable. A portion of the information then collected was shown by Admiral FitzRoy, in 1859, on the Wind Charts published by the Meteorological Department, which

face page 295

EE Rees eS

yy The red lines shew the general direction toa They are close in proportion to the velocity.

muuke the intervals or spaces between which the water moves, uv euch interval of 10 days. The arrows shew the daly velocity and. direction

Fa A.B Mean Isotherm between cs - Ar uso

pavakbireg- were

samp [he Guinea Curkent exter June,e Segre. Oct, $ or furtly

showed the phenomena for the months of February, May, August, and November, being the middle month of each seasonal quarter.

The discussion and integration of Current observations involve a great amount of tedious labour, and there is no question but that the data used by Rennell and others required much revision, as each succeeding and better estimate gives a lower rate of progress to the movement of the surface waters, though previous discussions as to their nature have been confirmed. In the remarks on the Meteorological Office Current Charts, Mr. R. H. Scott, the Director, says: - The number of observations em- ployed in the construction of the General Chart exceeded 7,500, each of which took 24 hours to make, so that some idea may be formed of the length of time required to accumulate them, and the great difficulty which is experienced in collecting information about Currents.

(240.) In this book, limited as it necessarily is to generalities, space could not be afforded to give the introduction of these Monthly Charts, but in the subsequent descriptions of each branch of Ocean Circulation in the North Atlantic we shall add the notes which elucidate the Current Charts, and which were also drawn up by Mr. R. Strachan.

In pursuing these calculations, it was found that in many localities the Currents were represented as most devious and erratic, frequently of great strength, and yet, on a mean, showing that there was no continued set of the waters in any special direction. The diagrams of the direction of the Wind at the Liverpool Observatory (page 203), in their more complicated parts, give a good notion of their motions, as their paths, when traced, resemble each other much. In other parts, as in the great Equatorial Current, the motion, as estimated, is remarkably uniform, and this demon- strates that these observations generally are entitled to confidence.

(241.) In founding any theories of circulation or movement of the ocean waters upon the basis of the (acknowledged to be) imperfect observations used by Major Rennell, it may be objected that many of them are now old, and therefore still less trustworthy. To this it may be replied, that they were mostly taken in wooden ships (with very little iron in them to affect the compasses) by careful navigators, in an age when great pains were taken with the dead-reckoning. A doubt may very fairly be expressed whether the observations of an equal number of modern ships would give as trust- worthy results; their greater speed, and less attention to D.R., more refined astronomy superseding it ; and errors in the compass owing to the iron used in the construction or cargo of the modern ship, all tend to give con- fidence in these old observations.

(242.) There is one general result in discussing any large number or collection of Current observations. They show that the surface water moves at a much lower velocity than has been attributed to Current motion generally. Perhaps this may in some degree arise from the fact that only those of remarkable strength have been selected, without properly taking into account the greater number of observations which would give a much more moderate rate.

(243.) Bottles - It has heen a well-known practice for many years to send these floating messengers as indicators of Currents. In 1843, Captain A. B. Becher, R.N., drew up a very interesting chart of the North Atlantic

with the points of ''despatch and arrival" of a very large number of these Current Bottles. The practice and the accuracy of the teaching of these Bottles led to a long controversy, which, however, did not tend to over- turn their authority, so it need not be longer adverted to here, than to say that the principal objection to them was, that they were rather impelled by the prevailing Wind than drifted in the Current. But this is also a demonstration of what can be otherwise proved, that the Winds and sur- face Currents of the Atlantic and other Oceans obey the same laws, and move very much in the same circuits. These Bottles, then, will form an important part of the subsequent demonstrations of the direction and rate of Currents. Captain Becher's chart bears intrinsic evidence of its trust- worthy character, as in each region the Bottles obey precisely the law which would, 4 priori, be laid down for them.

In July, 1891, the United States Hydrographic Office published a chart showing the tracks of a large number of Current Bottles* and Floats which had been recorded during recent years. This, also, confirms the accepted theory of the circulation of the Ocean.

(244.) Prince Albert of Monaco, assisted by Professor Pouchet, and a grant from the Paris Municipal Council, during the years 1885, 1886, and 1887, made a series of current experiments on board his sailing yacht Hirondelie, the results of which he communicated to the Paris Academy of Sciences, who published them in the '"'Comptes Rendus."" He also furnished a resumé of them to the meeting of the British Association, at Edinburgh, in 1892, published in the '' Proceedings of the Royal Geographical Society,"

The floats used were casks, pence globes, and bottles, weed to pre- vent their being acted on by wind, and containing the usual document. In 1885, floats Tenia 169 were launched along a line of 170 miles in a N. 14° W. direction from a position 110 miles N.W. of Corvo, Azores. In the next year, 510 floats were launched nearly along the meridian of 931 were launched along a line from the Azores to the Banks of Newfound- land, and 63 others in mid-Atlantic, between the Banks and the coast of

Of these floats, 227 had come to hand again, and their tracks, as shown on the chart drawn up by the Prince, appear to confirm the usual theory of the North Atlantic Currents. From them he concludes that the mean daily velocity of the Ocean currents is as follows : - The region comprised between the Azores, Ireland, and Norway, 3°97 miles ; between the Azores, France, Portugal, and the Canaries, 5:18 miles; from the Canaries to the West Indies, the Bahamas, and even to Bermuda, it attains a daily speed of 10:11 miles; and in the Eastern portion of the arc, which extends from Bermuda to the Azores, it falls again to 6°42 miles. The mean velocity which the combined results give for the surface circulation of the North Atlantic Ocean is 4°48 nautical miles in twenty-four hours.

* Bottles used far this purpose should be painted some conspicuous colour, weighted $9 43 to keep the corks out of the water, and securely sealed.

¢ Professor Pouchat published his observations in a book entitled "Courants de

face page 297.

Drift of Bottles, Derelicts, &c.

no Perceira

CVerde Isles Bonavts

Brava 3 "Tago

These exargples are splected trom the S.Pilot Chhprts ye Atlantic Ocean

- alt or

Fernando Noronha

Son peau

It is apparent that circulation is more active on the Western semicircle of the vortex than on the Eastern one; and this is explained by the com- bined action of various causes, as the Trade Winds, the Equatorial Currents, and the Gulf Stream, also the powerful evaporation which in the Tropics stimulates the circulation of the waters.

The accompanying diagram shows graphically the drift of some of the more remarkable Bottles, Derelicts, &c., recorded in the U.S. Pilot Charts.

(245.) It may be observed that this section deals chiefly with the Surface Currents of the North Atlantic Ocean, as that is the only feature which affects navigation. But this superficial action is not the only point to be considered in relation to Ocean Currents, as it will not explain many phenomena known to exist.e The researches carried on in H.M. Ships Inghtning and Porcupine, in 1868 - 1870, and Challenger, 1873 - 1876, under the superintendence of Dr. Carpenter, Mr. Gwyn Jeffreys, F.R.S., and Professor Wyville Thomson, LL.D., F.R.S., together with the more recent explorations carried out by government and private vessels of our own and various other nations, have thrown much light on the temperature, condition, and probable movements of the lower beds of ocean water, which will be alluded to at the end of this work. Indeed, this may be considered as a comparatively new branch of terrestrial physics, from which many most important facts will be derived.

(246.) That the waters of the Ocean do circulate over and intermingle with every portion of the water-surface of the globe is certain. Its com- position and character are syerywhere, in every region, almost exactly the same. This universality of character can only be accounted for by infer- ring that the Ocean waiters are continually being intermingled, as is the case with the atmosphere, before described (2), page 98.

It may be objected thst the specific gravity of the surface water varies considerably in different regions, and that it is therefore an argument against this intermingling of the sea-waters. But it will be found that there are local causes which affect the saltness of the surface water. In the Arctic regions, where it is frequently found of great density, or in- creased saltness, it is doubtless caused by the formation of Ice, subtract- ing the fresh water from the surface. Again, in the Equatorial regions, it is usually found of low specific gravity, or containing less salt, which may also be accounted for by the great rain-fall which, by intermingling the light fresh water with the surface, lowers its density. Very much specula- tion has been used on this variation in the surface density and on its dynamic effects, in producing currents and other phenomena.

But it is deferentially urged against this reasoning, that almost all the experiments made upon the density of the water at any considerable depth (above 20 or 30 fathoms) show a remarkable uniformity in the density in all regions, varying within very narrow limits, from 1:024 to 1:028 ata temperature of 60° F'., as will be shown in a later part of this book; and that, therefore, the real character of sea-water, below local influences, is everywhere nearly the same.

But we have remarkable proofs that not only the upper stratum, but also the whole Ocean to its bed is of one universal character. In recent deep-

sea exploring expeditions, samples of water have been brought up from the greatest and intermediate depths, and on analysis the components have been found to be in all cases almost identical, the exception being that at great depths the proportion of lime is larger. Animal life, also, is found at great depths, adapted to the great pressure under which it exists. Dtring the voyage of H.M.S. Bulldog, in the summer of 1860, when nearly midway between Ireland and Greenland, there were brought up from a depth of 1,260 fathoms, or nearly 14 statute mile, several live starfish, which had clasped their slender arms round that part of the sounding line which lay on the bottom. Now, as the process of winding this line in would occupy upwards of an hour, had the water varied in character even in a slight degree, they would have loosened their hold and died.

It is needless to pursue this subject further now. It will be found more amplified hereafter, when the question of the Depth of the Atlantic is dis- cussed. It is only here cited in order that should the mariner in the course of his voyage be able, from his own observations, to add to our knowledge of this subject, it will afford him great interest, and be beneficial to the rest of the world.

(247.) The subject of the Temperature of the Ocean will also be treated of specially hereafter. It is of importance in some localities, as it will indicate the changing from one Current to another, as from the Gulf Stream into the cold Arctic Current within it, or the reverse. It was formerly thought that a decrease of temperature was a sure indication of approach- ing shoal water, and its study was therefore inculcated as a precautionary measure. This point, however, has been shown to be in general fallacious. It arose from the fact that vessels crossing the Gulf Stream, or attaining soundings on the American coast, experienced a very sudden decrease of heat in the water. This is now accounted for in a very different way; therefore this topic is not of so much importance in the practice of navi- gation as it was formerly thought to be.

(248.) Leaving for future Sections (those on the Gulf Stream, and on the Depth, Temperature, and Circulation of the Ocean) the remarks on the origin and causes of Ocean Currents, it may be here briefly remarked that the action of the Wind seems to be a main cause of the general swrface circulation. Doubtless there are several other forces which combine with or help to neutralize the action of the Wind, such as the Tidal Wave, the rotation of the earth, the differing effects of Temperature, of Specific Gravity on the surface, and of the very difficult subject of wave-action, which should be taken into consideration. But the tiny ripple raised by a breath of air on the surface of still water, enlarged by accumulation into an oscillating wave by a more powerful wind, may be driven forward into a wave of translation, and thus the Wind becomes the real origin of a Drift and finally a Stream Current, which may be satisfactorily traced over a great portion of the Ocean surface.

(249.) There are many evidences that the general surface Currents, which alone control a ship's movements, have but very little depth. A very few fathoms below the surface their velocity and power become much decreased, and it is more than probable that at a moderate depth, com- pared with the dimensions which have been usually attributed to them,

they cease altogether, or become imperceptible to ordinary means of measurement. This has been found to be eminently the case in the expe- rience gained in laying submarine telegraph cables. If the motion of the surface water were continued to any great depth, or if there were change- able and varying sub-surface streams, it would very greatly interfere with the success of these enterprises, but no such obstacles have shown them- selves to be of any magnitude.

(250.) Of Currents there are two distinctions : - 1. The Drift Current ; 2. The Stream Current.

The Drift, or Drift Current, is the mere effect of a constant or very pre- valent Wind on the surface water, impelling it to leeward until it meets with some obstacle which stops it, and occasions an accumulation and consequent Stream of Current. It matters not whether the obstacle be land or banks, or a Stream of Current already formed. The Drift Current is generally shallow, and at a mean, perhaps, of no more than half a mile an hour, when the wind is constant and a good breeze. Such a Current, from a predominance of Westerly winds, occupies the Northern region of the North Atlantic, from the N.W. and West to the E.N.E. and S.E.; and such, likewise, is that occupying the central portion of the Ocean under the influence of the Trade Winds.

The Stream Current is formed by the accumulated waters of a Drift Current. It is more limited, but it may be of any bulk, or depth, or velocity. Of such is the temporary stream setting at times from the Bay of Biscay to the West of Ireland ; and of such is the Gulf Stream, setting from the Mexican Sea to the Banks of Newfoundland, and terminating to the West of the Azores.

In some parts the Current is compounded of Drift and Stream; for a Stream, already formed, may pass through the region of a prevalent wind, in a direction according with that of its Drift Current, and receive an acceleration of motion from it accordingly. Of such are the Equatorial Currents, which will be presently noticed.

(251.) The illustrative chart at the commencement of this section, page 295, will best explain the general Current system of the North Atlantic Ocean. Although this gives the mean of all observations throughout the year, and therefore would require considerable modification in various parts, if it were made to show what is to be expected at any special time or season, yet it will correctly represent that circulatory system which is found to be common to all the Oceans.

There appear to be two gyrations of the water of the North Atlantic Ocean. Around a central area, crossed by the parallel of 30° N. latitude, and termed the Sargasso Sea, the whole of the water between lat. 10° N. and 42° or 43° N., limits varying with the seasons, revolves against the apparent course of the sun. To the North of this, a portion of the water is deflected to the N.E., and revolves around some point not very far from Iceland, though some have considered that, after circulating around the Arctic basin, it re-enters the area on the West.

As the meteorological Equator, or the division between the phenomena of the Northern and Southern Hemispheres, lies to the North of the terrestrial Equator, we find that a reverse current, of varying magnitude

and force, runs from West to Hast on this division, or from 2° or 3° to 8° N., across the whole breadth of the Ocean, and along the African coast ; while, to the South of it, the Westerly Current of the South Atlantic runs across the Ocean and along the Northern face of the South American continent, a portion thus entering the Northern circulatory system.

There is then some difficulty in assigning a separate designation for each part of what is almost a continuous stream, and in former times when the . subject was much less understood, some inappropriate terms were applied to various portions, and have become recognized and followed throughout. For the present, therefore, we are compelled to use a somewhat confused nomenclature, but it will be sufficiently explanatory till a general revision of the science may impose a new terminology.

As before stated, the charts drawn up by Mr. R. Strachan, for the Meteorological Office, will be considered as the ground-work of this section, but with some modifications of the nomenclature used.

(252.) Of the Current regions of the North Atlantic Ocean, the first in order, from the Land's End of England, is Rennell's Current, a temporary but extensive stream, which sets at times from the Bay of Biscay to the Westward and N.W., athwart the entrance of the English and St. George's Channels, and to the Westward of Cape Clear.

Second. - The Easterly and S.H. Currents to the coasts of Hurope and Africa, and Southerly to the coast of Guinea, where it may be termed the North African Current, flowing to the Westward of South, and merging into the Westerly Drift.*

Third. - The Guinea Current, an Easterly stream across the Atlantic, between 5° and 8° N., and continuing along the coast of Africa, into the Bights of Benin and Biafra.t

Fourth. - The Sargasso Sea, or central area between the Azores, Canaries, and Bermudas, &c., in which it seems that there is no particular drift or very various and nee currents, and it is covered with the well-known Sargasso or Gulf-Weed.

Fifth. - The North and South Equatorial Currents, the vast streams caused by the Trade Winds. That of the N.H. Trade, running from between the Tropic and Cape Verde, on the Hastern side, towards the Caribbee Islands, having a general Westward tendency; and that from the S.E. Trade, which is usually found to the North of the Equator, pass- ing strongly to the Westward, South of the counter or Hasterly Guinea

* This Southern set along the coast of Portugal and N.W. Africa is a faint converse of the Gulf Stream on the opposite side of the circulatory system. The Northern portion of it was termed by Rennell the North Atlantic Current, as trending from the termina- tion of the Gulf Stream to the coasts of Europe, &c. (Investigation, &c., page 53). In the Meteorological Office Work, 1872, it is called the North African Current. For the present, the name which has been applied in former editions of this work is provisionally

+ Since it has been established that this Guinea Current has a different origin and character to that assigned it by Rennell and others, who argued that it was a continua- tion of the North African Current, the term in some degree is a misnomer. It is an Equatorial Cownter-Current, which is found in some seasons to run across all Oceans, This origin was first intimated by the author in 1853.

Current, and then strongly to the W.N.W. along the Guayana and Colom- bian coasts, part joining the N.E. Trade Wind Current Northward of

Sixth. - The Currents of the Colombian or Caribbean Sea, a continuation of the Great Equatorial Streams into the Mexican Sea, from the South- Eastward and Hastward.

Seventh. - The Gulf Stream, an outset from the Mexican Sea, setting thence to the North-Hastward, through the Strait of Florida, and thence Eastward toward the Newfoundland Banks, &e.

Highth. - The North-East Drift, which passes over the Eastern side of the Atlantic, from the area East and South of the Newfoundland Banks towards and past the N.W. Coast of Europe and into the Arctic Basin.

Ninth. - The Arctic or Labrador Current, passing Southwards from Davis Strait down the coast of Labrador, round Newfoundland, and thence South-Westward past Nova Scotia and the coast of the United States inside the Gulf Stream.

In explaining this subject, we shall endeavour, in the first place, to establish the facts which prove the existence of these Currents, and then attempt to deduce the causes, according to the given description.

(253.) Masters of vessels are sometimes disappointed in not finding the expected set and velocity of the normal Currents. At times the set may be directly opposite to that looked for, or no Current at all may be found, even in the area traversed by the Gulf Stream ; but these irregularities are usually of short duration, being due to abnormal meteorological con- ditions and other causes.

(254.) In the Bay of Biscay, the prevalence of N.W., West, and S.W. winds causes a heavy swell and considerable current, needing due con- sideration. The waters of this gulf have a vast gyratory movement, irre- gular in outline, and variable in velocity, on account of the considerable effect of different winds. The S.H. current, setting on to the N.W. point of the Spanish peninsula, is divided there into two branches, one setting South along the Portuguese coast, and then turning to the Eastward about Cape St. Vincent; the other setting East along the North coast of Spain, and North along the West coast of France, where it is 15 or 20 miles across, and is felt at 30 or 40 miles off shore: it becomes wider as it pro- ceeds Northward, and is probably joined at times by the streams from the rivers of France. On the parallel of about 48° 20' N. it is about 80 miles across, and the set, following the coast line, is nearly W.N.W., passing 15 or 20 miles from Ushant and across the entrance to the English Channel, where it is called Rennell's Current. The commotion of the waters at the time of the flood tide in the Channel, all along the line of separation, has

undoubtedly given rise to most, if not to all, the reports, formerly quite frequent, of rocks and broken water in this vicinity. It is hardly necessary to add that all search for such dangers has been unavailing.

The currents on the N.E. extremity of Spain, about Corufia, where the Eastward drift is separated into two branches by the projection of the land, are generally governed by the winds. The coast is thus dangerous in those which come from North to West, and where they are light and the sea heavy it is best to keep well off shore, otherwise the outer rocks may be passed at 2 miles distance.

To the Eastward of Cape Ortegal, and at a considerable distance from shore, but at what distance cannot be well defined, the Easterly or N.E. current is constant, and it also runs with great velocity, quite overpower- ing the effect of the tide. With N.E. winds, but not with others, this Easterly drift is found close inshore. The current very rarely runs to the

The drifts are more sensible to the East of Cape Penas than to the West. They generally run to W.N.W. in the summer, and to Hast and E.N.E. constantly in the winter. A strong Easterly current is a sure pre- monitor of a N.E. gale.

On the Biscayan coast the drift is to the Kast during the winter season, impelled by the constant S.W. and N.W. winds.

The current frequently attains a rate of more than 3 miles an hour, when a strong gale from N.W. has occurred. A strong Easterly current during calm and serene weather is generally the precursor or indication of a gale. or squall from N.W. From the same cause a very high tide may be looked for in all the harbours.

In summer the current often runs to West and W.N.W., but with little velocity, so that it may be taken almost as a general rule that the current is constantly to the Hast at a certain distance off the land, as before stated.

The farther you proceed up the Bay of Biscay towards Bayonne, the currents increase in strength, and turn to N.H. and North up the coast of France. Their rate is much increased by a N.W. gale, when they attain a velocity of 4 miles, and sometimes more than 5 miles an hour, accord- ing to the local seamen. The rapid drift of this Northerly current during winter gales, which always blow from $.W., will explain how the innu- merable wrecks occur on the banks off Arcachon and Cape Breton.

(255.) Rennell's Current, which is occasionally of considerable breadth and strength, frequently sets athwart the entrances of the English and St. George's Channels to the N.W. and W.N.W., at some distance to the Westward of the Isles of Ushant and Scilly. As it apparently depends on temporary circumstances, it is considered as a temporary stream ; and, although a certain quantity of Northerly indraughtis always to be allowed for, with the tide of flood, on approaching the Scilly Islands, on the Ocean the Current, unless with particular winds, will be scarcely, if at all, per-

The general causes of Currents, so far as they depend upon the state of the Winds, &c., are generally known to seamen; and that a long-continued wind, in one particular direction, will either produce a stream where no obstruction exists, or cause an accumulation of the water against an

opposing coast, until a reverberation takes place, needs no demonstration. The latter appears to be the case in the present instanee. A long and continual prevalence of Westerly and South-Westerly winds, in combina- tion with a current that commonly sets into the Southern part of the Bay of Biscay, occasions an accumulation of water in the Bay, which seeks an escape, by setting to the N.W. or W.N.W.

It would be very difficult to understand that the great preponderance of winds from the Westward of North and South, which prevail in the latitudes off Cape Finisterre, should not have some effect in forcing the water toward the coast ; and, if so, what can become of it, unless it forms some Current, which we should very naturally expect to find would follow the trend of the coast against which it is propelled.

That such a Current does actually prevail is too well known to be doubted. Mr. Kelly, the author of a treatise on Navigation, in two volumes, pub- lished in 1733, gave a particular instance of it (Vol. i., page 434); by which he shows that a ship becalmed with her sails furled for forty-eight hours, was in that time carried by the current 46 miles to the Northward; and we have many subsequent examples of vessels which have been set, by the,course of the stream, to the Northward, or upon the rocks, of Scilly. But the writer to whom we are more particularly indebted for an elucida- tion of the subject, is the late Major RENNELL,* who gave an illustration of it, which placed it beyond all controversy ; and from whose paper, pub- lished in the '' Philosophical Transactions" of the year 1793, we extract the following observations : -

'Tn crossing the Eastern part of the Atlantic, the Hector, Kast India ship,

* From the name of this gentleman, the Current is now generally denominated RENNELL's CURRENT. The Currents of the Ocean appear to have attracted the atten- tion of Major Rennell at an early period, and they continued to occupy his attention until the last ebb of his honourable life. The results appeared before the world in five large charts, with a descriptive volume, dedicated to his Majesty King William the Fourth, under the editorship of Mr. John Purdy, the original author of this volume.

The Major's first Chart and Remarks on the Agulhas or South African Current appeared in the year 1778, and the important pamphlet on the Scilly or 'thwart Channel Current, in the year 1793. In the meantime, and subsequently, some cursory remarks on the same subject were introduced in the 'Illustration of the Geography of Herc- dotus,'"' the Philosophical Journals, &c. In or about the year 1810, on the suggestion of a friend (Mr. Purdy), who expressed a wish to see all his writings on this subject com- bined and republished, he commenced his Cwrrent Charts of the Atlantie Ocean, and col- lected from the journals of his numerous friends a gleaning of information which, at length, from repeated accumulations, presented a most beautiful and singular instance of successful perseverance, on a subject never before attempted upon a plan so compre- hensive. To an ordinary mind such a topic would have been regarded as dull, unin- viting, and impracticable ; by the author it was appreciated according to its importance and usefulness to mankind, and he treated it accordingly. He had long lamented the general ignorance prevalent on this subject, and which had, from time to time, produced so much loss of lifeand treasure, especially in relation to his native country. It is true that, in later times, practice and experience had taught the mariner, in many cases, how to shape his course to the best advantage ; but still he was deficient in theory, and knew not the rationale, the why and wherefore, of the courses which he adopted, and the variations which might be most advantageously made in his outward or homeward passages, according to the fluctuations of season and circumstances. Such knowledge is now, in a great measure, supplied.

Captain Williams, in 1788, encountered, between the parallels of 42° and 49°, very strong Westerly gales; but particularly between the 16th and 24th of January, when, at intervals, it blew with uncommon violence. It varied two or more points, both to the North and 8.W., but blew longest from the Northern point; and extended, as subsequently appeared, from the coast of Nova Scotia to that of Spain.

"Within 60 or 70 leagues of the meridian of Scilly, on the 30th of January, between the parallels of 49° and 50°, the effect of the Current was first experienced, which set the ship to the North of her intended parallel, by nearly half a degree, in the interval between two observations of latitude; namely, in two days. The wind, ever afterward, prevented the ship from regaining the parallel; for although the Northern set was trifling, from the 31st until she arrived near Scilly, yet the wind, being scant and light, never enabled her to overcome the tendency of the Current. It is also to be observed that the direction of the Current was much more Westerly than Northerly; the ship crossed it on so very oblique a course as to be in it a long time, and was driven, as it appears, nearly 90 miles to the West by it; having soundings in 73 fathoms, in the latitude of Scilly, and afterwards ran 150 miles by the log, directly East, before she reached the length of the Islands; running, in effect, 120 miles, and shallowed the water only 9 fathoms.

«The Current was not only sensible by the observations of latitude, but by ripplings on the surface of the water, and by the direction of the lead line. In consequence of all, the ship was driven to the North of Scilly, and barely able to lay a course through the passage between those islands and the Land's End.

"There being no timekeeper on board, the longitude was uncertain ; but it was concluded that the Current, at times, extends to 180 miles West of Scilly, and runs close to the West of the islands. The breadth of the stream, where the Hector crossed over it, was supposed to be about 90

'A journal of the Atlas, East India ship, Captain Cooper, furnishes much clearer proofs, both of the existence of the Current, and the rate of its motion. This ship, outward bound, in January, 1787, had advanced 55 leagues to the Westward of Ushant, when violent gales began at South, and for four days continued between that point and W. by 8.; during

Among the names of the contributors to the work on the Currents, that of General Edward Sabine is conspicuous. In the year 1825, this gentleman published his Account of Experiments to determine the Figure of the Earth by means of a Pendulum vibrating seconds in different Latitudes, as well as on various subjects of philosophical enquiry, in which he refers to the subject of Ocean Currents in the following terms : -

"On a general review of the Currents particularized on the Pheasant's progress (in 1822) in her voyage, commencing at Sierra Leone and terminating at New York, it was found that she was indebted to their aid, on the balance of the whole account, and in the direction of her course from port to port, not less than sixteen hundred geographical miles, the whole distance being nine thousand, affording a very striking exemplification of the importance of a correct knowledge of the Currents of the Qcean to persons engaged in its navigation; and, consequently, of the value of the information in the acquisition ard arrangement of which Major Rennell passed the latter years of his most useful life."

which time the ship was lying-to, with her head N.W. On the fifth day the wind abated, but was S.W.; stormy weather then ensued for nine days, the wind blowing from all points between South and §.8.W., but chiefly, and most violently, from W.S.W. and 8.W.; and when the ship then proceeded Southward on her voyage, she was, by reckoning, only 23° of longitude West of Cape Finisterre; but, by timekeepers, more than 44°.

'On the day the gale commenced, the reckoning was within fourteen minutes of that by the timekeepers ; the latter beimg more Westerly, owing to the current. On the third day after, the difference was about twenty- four minutes, when the ship was 75 miles §.W. from Scilly, in soundings of 76 fathoms. The ship, in longitude 8° 28', had entered into the stream; and, her course being opposite to that of the Hector, it facilitated her pro- gress, and carried her clear of the S.W. coast of Ireland.

'« After this, in the course of fifty-one hours, the ship had set two whole degrees to the Westward of her reckoning ; and in the forty-five hours fol- lowing, she had a further set of twenty-three minutes; so that, in four days only, she had been carried by the Current no less than 2° 23'; and, since the gale began, 2° 32' of longitude, or 93 nautic miles.

'"' Tt consequently appears that the Atlas experienced a Westerly Current, from about 72 miles W.S.W. of Scilly, to near 4° of longitude West of the meridian of Cape Clear, where its effect was imperceptible. It may, there- fore, be inferred, that the stream goes off to the N.W. in the parallel of 51°; between long. 14° and 15°, and the S.W. coast of Ireland.

''No Northern set is indicated in the journal of the Atlas. This would have been remarkable, had the weather permitted nice attention to the reckoning; but it is to be remarked, that observations on the latitude were not regularly made; and, besides, that the great distance of 36 miles was allowed for only twenty hours' drift to the N.W., when the ship was lying-to.

'From the nature of this Current it must be obvious that its velocity will always be proportionate with the strength and direction of the wind, by which its direction will always be eared and that the middle of the stream will preserve its original course in a greater degree than its borders. The direction of this appears to be N.W. by W.; the Eastern border more North; and the Western more West; so that the Northerly current is stronger close to the West of Scilly than more to the Westward.

''From the foregoing observations may be deduced the following in-

"1st. That ships, which cross the Current obliquely, steering a true E. by 8S. course or more Southerly, will continue longer in it, and be more affected by it, than those which steer more directly across it. In crossing it with light winds, the effect will be the same. Allowance must be made for the more Northerly direction of the Eastern edge of the Current.

"9nd. That, after the continuance of Westerly gales, even should a good observation of latitude be made, it would be imprudent to run Eastward from the Atlantic during a long night. For a ship might remain in the Current so long as to be drifted from a parallel, deemed a very safe one, to that of the Rocks of Scilly. It is, therefore, recommended that vessels, at

such times, should keep, at the highest, 48° 45', because in 49° 30' the whole effect of the current may be experienced in the worst situation. But from the Current in 48° 45', a Southerly wind will set the ship into the Channel. Coming from the Atlantic, it would be still better to make

"3rd. That ships, bound to the Westward from the Channel, with a South-Westerly wind, so that it may appear indifferent which tack they go on, should prefer the port tack, as they will then have the benefit of the

(256.) In a Supplementary Paper on the effects of Westerly Winds in raising the level of the English Channel, dated 22nd June, 1809, Major Rennell stated : -

'' In the observations on a Current that often prevails to the Westward of Scilly, which I had the honour to lay before the Royal Society many years ago, I slightly mentioned, as connected with the same subject, the effects of strong Westerly winds, in raising the level of the English Channel, and the escape of the superincumbent waters, through the Strait of Dover, into the then lower level of the North Sea.

'' The fact of the high level of the Channel, during strong winds between the West and §.W., cannot be doubted; because the increased height of the tides in the Southern ports, at such times, is obvious to every discern- ing eye. Indeed, the form of the upper part of the Channel, in particular, is such as to receive and retain, for a time, the principal part of the water forced in, as may be seen by the chart; and as a part of this water is con- tinually escaping by the Strait of Dover, it will produce a Current, which must greatly disturb the reckonings of such ships as navigate the Strait, when thick weather prevents the land, or the lights of the Forelands and the Goodwin, from being seen.

'There is another circumstance to be taken into the account, which is that the shore of Boulogne, presenting a direct obstacle to the water im- pelled by the Westerly winds, will occasion a higher level of the sea there than elsewhere ; and, of course, a stronger line of the Current toward the

'Tt must, therefore, be inferred, that a ship passing the Strait of Dover, at the back of the Goodwin Sands, during the prevalence of strong West or S.W. winds, will be carried many miles to the Northward of her reckon- ing; and, if compelled to depend on it, may be subject to great hazard from the Goodwins.

'Tt will be understood, of course, that although the stream of Current alone has been considered here (in order to simplify the subject), yet that, in the application of these remarks, the regular Tides must also be taken into the account. But, from my ignorance of their detail, I can say no more than that I conceive the great body of the Tide from the Channel must be subject to much the same laws as the Current itself. The opposite Tide will, doubtless, occasion various inflections of the Current, as it blends itself with it - or may absolutely suspend it; and the subject can never be perfectly understood without a particular attention to the velocity and direc- tion of the Tides in moderate weather, to serve as a good groundwork."

(257.) After the publication of the first paper on the Currents of the

English Channel, and the supplementary paper immediately preceding, Major Rennell published some further important observations upon it, which were read before the Royal Society, April 13th, 1813, and from which the following extracts are taken : -

'' During the interval of twenty-one years, since the Society did me the honour to receive my Observations on the Current to the Westward of Scilly, more facts relating to that Current have been collected, as well as obser- vations on its effects, in different parts of its course, between Cape Finis- terre and Scilly, the whole tending to confirmation of the general system set forth in 1793 ; and, in one instance, affording perhaps a clearer proof of the strength of the stream, in respect to its Northerly direction, than any of eco adduced on the former occasion.

'In pursuing the detail of these facts and observations, I shall noeae in the neighbourhood of Cape Finisterre, and proceed with the course of the Current along the Bay of Biscay ; and thence across the mouth of the English Channel to Scilly, and the entrance of St. George's Channel.

'"' The first three facts (not detailed here) regard the Current from the open sea, setting into the South side of the Bay of Biscay, and along the North coast of Spain ; which Current was supposed, in the former paper, to be occasioned by the prevalent Westerly winds, which force the water near the shore into the bay, and along the Southern coast of it. The water 80 displaced would be followed, of course, by the adjacent water behind it, in the open sea; and so on successively, to a certain extent. This cause must surely be referred to as the origin of the Scilly Current. The three facts converge, as it were, to one point; that is, in the proof that the waters of the Atlantic flow into the Bay of Biscay, along the North coast of Spain.

'Tt would seem that the North-Westerly current, by Scilly, did not, at least in many cases, balance the Easterly current round Cape Ortegal and the land of Finisterre.* The loss of His Majesty's frigate Apollo, with most of her convoy, may surely be attributed to the operation of this Current. Captain (afterwards Commissioner) Wallace assured me, that after having made, as he supposed, ample allowance for clearing Finisterre, yet, in the night, he had a very narrow escape from shipwreck. Very many others have been brought into the same kind of danger; so that the land of Finis- terre, were it not discernible at a considerable distance, and its offing clear of rocks and shallows, and, moreover, situated in a finer climate, would prove a kind of Scilly to mariners.

"'T have not been able to obtain any proofs on record concerning the course of the Current rownd the Bay of Biscay. I formerly collected some information from a French commander respecting it. He said that the setting of the Current along the coast of France, to the North and N.W., was a fact well understood, and even acted on, by many in the choice of the tack, on which the Current gave the greatest advantage with head winds.

* Nor, admitting an equal rate in both places, could it well be. For the Current enters the Bay of Biscay in an Kast direction, but goes off from it V.W.; so that, if a ship were carried 50 miles to the N.W. from Ushant, she would only have made about 35 miles westing ; but, in the other case, she would be carried tha whole 50 miles East- ward, toward the Bay and Cape Finisterre.

"' One circumstance, and that a very striking one, in respect to this par- ticular, is, that the soundings in the Bay of Biscay show little or no muddy bottom to the Southward of the Gironde Riwer, but everywhere to the Northward. This seems to show that the mud of the Gironde, Charente, Loire, &c., &c., is all carried to the Northward ; and by what cause but a Northerly current? Had the motion of the sea been variable, the mud would surely have been distributed to the South, as well as to the North, of the mouth of the Gironde. The alluvial embouchwres of the rivers in general here, and the positions of the banks formed by them in the sea, point to the North or N.W.; apparently the effect of the same sea-

(258.) From experiments made by Prince Albert of Monaco, in his floats of peculiar construction, he considers that during the summer there is no current setting East along the North coast of Spain, and thence to the Northward. On the contrary, his experiments show that the Current sets §.S.E. into the Bay of Biscay, and then due West along the North coast of Spain around Cape Finisterre. As before stated, there is no doubt that this Current largely depends upon the prevailing winds.

(259.) Caution - Great caution is necessary when approaching the parallel of Cape Finisterre from the Northward, on account of the pro- bable indraught into the Bay of Biscay, and no favourable opportunity should be lost for ascertaining the error, if any, of the navigating compass. Great loss of life and property annually occurs on this coast,+ through

* From a view of the Chart of Soundings between Spain and Ireland, one might be led to suppose that the deep water and steep shore along the North coast of Spain had been partly occasioned by the water driven in from the Atlantic, in Westerly storms, along that coast ; and which had gradually worn away the matter there, and deposited it on the bank which extends from Bayonne to the Westward of Ireland. For the bank seems to expand, as it goes Northward, in like manner as the Current; and the water is shallower than might be expected, in proportion to the depths farther in.

+ During the five years 1888 - 1892 inclusive, 176 British merchant vessels were wrecked on the North and West coasts of Spain and Portugal.

Our readers will not fail to remember the loss of H.M.S. Serpent, with only three sur- vivors out of the crew of 176. She struck at 10.30 p.m., November 10th, 1890, under Cape Villano, and at once broke up. The finding of the Court Martial which investi- gated the loss was, that it arose from ''an efror in judgment of those responsible for the navigation of the ship, in not having shaped a course sufficiently to the Westward."

In connection with this, it may be stated that H.M.S. Lapwing, on the following night, unexpectedly made the land near Cape Villano, having previously during the day ascertained by a momentary glimpse of the sun that the vessel had been set 60 miles out of her course into the Bay.

Again, early in the morning of February 7th, 1893, the Anchor Line steamer Trimacria was wrecked in the same locality, from the same cause, with the loss of thirty- four lives, only seven of the crew and oae passenger being saved by swimming ashore. The vessel was on the rocks and amidst the breakers almost before those on board had time to apprehend danger.

Case after case could be recorded, showing that though the dangerous character of the current hereabout is known, due allowance for it is not always made, in some cases with fatal resuits. Some further remarks and cautions are given hereafter, in the Section on Passages, showing that danger might be averted by the use of the deep-sea

vessels crossing the Bay, on their course to the Southward, trusting blindly to the course set to clear all danger, even at night, while the insidious force of the Easterly Current has set them many miles to the Eastward of their supposed position. Disasters have occurred here, both by day and night, to all kinds of vessels, from the small coaster, with its imperfect appliances, to the British man-of-war with every aid to naviga- tion at its disposal, and this within the last few years.

Some have considered that these losses might be due to local attraction of the compass, but numerous observations by officers of the French navy and others have established the fact that no such irregularity in the devia-

Captain C. MacMahon, of the Clan Line steamer Clan MacArthur, in the Standard of March 18th, 1893, remarks : - '' The interest which has been aroused by the late wrecks about Cape Finisterre and on the coast of Portugal is, by public inquiry, demanding the cause of these disasters.

"There can be no doubt that the primary cause is bad weather and overcast sky, when crossing the Bay, preventing commanders of vessels getting sun or stars to fix their position or correct their compasses by. The secondary cause is the difference of opinion among nautical men about the amount of indraught into the Bay caused by the Easterly Atlantic current and increased' by Westerly winds and gales. To this is added the leeway a vessel makes. To get an approximate value of the combined in- draught and leeway is of the utmost importance. A most favourable instance occurred with this vessel on her present voyage for testing the indraught and leeway at its maximum point.

"We left Liverpool on the 16th ult. Until 6 a.m. on the 19th we had strong Southerly and South-Westerly gales, with high seas, Westerly swells, and overcast weather. The wind shifted to N.N.W. on the 19th, so that we got a good position by observation at noon, lat. 44° 24' N., long. 9° 49' W. From this position, a straight line due South true passes 23 miles West of Cape Finisterre (90 miles South) and 12 miles West of the Burlings. It was blowing a fresh gale at the time, with a high sea and Westerly swell.

'"« At 9.32 p.m. on the 19th, Cape Finisterre bore S. 83° E. true, distant 12 miles. I had allowed 8°, or three-quarters of a point, for leeway and indraught to make a trwe South course. In other words, since noon, in a 90 miles run, with an allowance of three-quarters of a point for all causes, Twas set towards the land 11 miles, passing Finisterre 12 miles West instead of 23 miles. This, I think, was a fair test of the maximum in- draught and leeway about Finisterre."'

(260.) Inset into the Bay of Biscay. - A Bottle from the Lady Louisa, bound to St. Michael's, in lat. 45°, long. 13° 45', February 2nd, 1830, was found on the coast of Lit, in the province of Bayonne, October 14th, in the same year.

Channel Soundings into the Bay. - A Bottle from the brig Hope, from Havannah, three days ; was found on June 1st, 1838, on the coast of Rochefort, having pro-

bably been first impelled to the S.W. by the ebb tide and prevalent wind, and thence following the general inset to the South and East.

From Channel Soundings to the West of Scotland. - A Bottle thrown from the ship Duke of Marlborough, Captain Jeffery, by Mr. George Thom, near the Sole - Bank, in lat. 48° 38', long. 9° W., was found on the shore of Carsaig, near the middle of the South side of the Island of Mull, April 14th, 1821, and made known by Mr. Hector Maclean. At the time this Bottle was thrown into the sea, the ship was bound to London from the Cape of Good Hope, and an allowance was made for Current to the N.W. of 12 miles in the twenty-four hours. From the spot in which it was dropped, it seems unquestionable that the Bottle was carried by the Current to the West and North of Ireland, and thence between Islay and Mull, to the place in which it was found. It, therefore, well answered Mr. Thom's purpose of confirming Rennell's Current.

Bay of Biscay to the North of Scotland. - A Bottle, enclosing a song composed on board, from the Great Western steamer, on her voyage to New York, at mid- Captain Thornton, of the Ceres, in passing through the Pentland Firth, on the 16th of the same month. It must, therefore, have drifted to the North- Westward and Northward, off the Western coast of Ireland, and thence to the N.E. and East, by the general drift from the Greenland Seas.

St. George's Channel. - A Bottle from the ship Osprey, of Glasgow, Alexander M'Gill, master, which sailed from Greenock. This Bottle (No. 310) was thrown into the sea, March 1st, 1822, on the ship's return from Calcutta, in lat. 49° 54' N., long. 12° 20' W. It was found on the shore, upon the South side of Milford Haven, on the 6th of the following month.

Easterly Current to Bristol Channel. - A Bottle from the brig Albert, R. L. sage from Virginia to England, the wind then about W.N.W., and had so pre- vailed for two or three days. Found in Rockham Bay, about 4 miles West from Ilfracombe, July 29th, 1822, and attested by the agents to Lloyd's.

Bay of Biscay, North Side - A Bottle thrown from the ship Graham Moore, on the coast of St. Jean de Mont, arrondissement of Sables d'Olonne, department of La Vendée ; and made known by the Journal de Paris. This bottle was im- pelled in an E.S.E. direction, the North- Westerly current not then prevailing, and was within the influence of the Tide. "

By Captain Livingston's Journal, November 28th, 1820, 'It appears that in 24 hours, ending at noon of yesterday (on the passage from Gibraltar), we made about 15 miles North by current ; and in 24 hours, ending at noon this day, about 13 miles North, and in the two days rather more than 20' E. Therefore, about

Inset to, and Outset from, the Bay of Biscay. - A Bottle from the Jris, Captain Skinner, in lat. 47°, long. 21°, September 9th, 1802, was found at the Isle of Skye on an Eastern direction, subsequently Northward by Rennell's Current, and thence by the Eastern Drift to Scotland).

The ship Jessie, Bevan, master, left London for the Bahamas, about November 18th, 1833. She was struck by lightning, and abandoned by her crew, in lat. 45°, Jong. 14°, and on February 5th, 1834, drove on the Isle de Groiz, near L'Orient, and was immediately dashed to pieces.

Inset ; Bay of Biscay. - A Bottle from the Carshalton Park, Lieutenant J. Steele 1827, on the shore of Pembron Road, near the Loire, in the Bay of Biscay, lat.

from S.W. for five days, a fresh gale, and then S.W. Another Bottle from the on the 25th of February, 1839, on the shore of Arcachon, in the Bay, lat. about

A metal cylinder, cast from H.M.S. Chanticleer, Captain H. T. Austin, May 8rd,

of Spain, 12th of September following, at about 150 miles from the spot where it was dropped into the sea. .

A Bottle from the bark Mary, of London, Abyah Locke, master, April 12th,

was found near Cape Ferret, 44° 38', February 21st, 1833.'

A Bottle thrown over from the Wellington, August 23rd, 1837, in lat. 45° 10' N., long. 12° 58' W., was thrown on the South coast of the Isle of Ré, probably about the end of February, 1838; found March 2nd, 1838.

Tide Water on Soundings. - A Bottle from the bark Wallace, of Alloa, bound to 5 miles from Ushant, August 21st, 1835.

1836, was picked up near Cape Blancnez, a few miles from Boulogne, December 20th, in the same year.

Bay of Biscay, South Side. - A Bottle from the schooner Morning Star, of Liver- pool, Captain Andrew Livingston, October 7th, 1821, lat. 42° 45' 39" N., long. 13° 3' 21" W., was found about 22 miles to the Northward of Bayonne, lat. 43° 58' N., long. 1° 20' W., and made known in the Moniteur of January 24th,

One of the most singular routes of the kind that we have met with was a Bottle covered with barnacles, picked up at Mizen Head, on the 8.W. coast of Ireland, October 19th, 1837. Its enclosed note stated that it was dropped off Cape Horn, from the Salem, R. Crukers, master, of the United States, in lat. 53° 3' S., long.

(261.) Velocity. - The daily rate of the inset into the Bay of Biscay, as estimated from the drift of the Bottles quoted in Captain Becher's chart, (243), is as follows : - (The numbers refer to Bottle Chart in the Nautical Magazine for November, 1852) - No. 2 (drifted 250 miles) 4-8 miles per day; longest courses have the quickest rates, so we may suppose that when the ' Bottles become entangled in the shore tides and devious drifts, they do not travel so fast in direct distance. The mean rate of all these Bottles is 3:26 miles per day. The rate of those which travel up the English Channel is very much greater, averaging 11 to 14 miles per day.

The foregoing are the principal arguments and facts from which the existence of the 'thwart Channel Current is inferred. That there is some cause for the drifting of the various vessels, &c., in a Northward and West- ward direction, there can be no doubt; nor can there. be any doubt that

the stream varies both in strength and in direction. Without enquiring into the sufficiency of the cause to produce these effects, or of the correct- ness af the views promulgated by Major Rennell, the foregoing remarks have been repeated, as originally given; and here we would add, that they were formed long before any correct knowledge of the Tides or of the Tidal Currents was acquired, and also that a very just estimate of the amount of derangement of the regular Tides, or of the set of the Current across the mouths of the English and St. George's Channels, is formed from his dissertations. The remarkable revolution of the tidal streams at the entrance of the English Channel, caused by the cross-action of that wave proceeding up the English Channel with that of the wave coming Northward, has been well developed in the observations discussed by Admiral Beechey, as stated on page 285.

(262.) The Currents on the shores of the North Atlantic Ocean seem to have different tendencies to the South and North of the English Channel. They are certainly very devious and uncertain ; but along the West coast of Ireland and Scotland, as well as in the offing, the general set is to the Northward. Off the Southern part of the Bay of Biscay there is a well- marked Current to the S.E. and Sowthward, not only during those periods when the Westerly winds have been prevalent, and causing the Rennell's Current, last described, but it appears to be constantly met with; and, \herefore, in sailing Southward from British ports, this tendency of the waters should be carefully considered, especially when the shores are neared, for there they run strongest.

(263.) As stated hereafter, this well-marked Current was considered to be a portion of a stream, which, running to the Southward and Hastward along the African coast to the Bight of Biafra, was the head of the Guinea Current. But in a discussion on the general system of Ocean Currents,* it was shown to be exactly analogous to an Equatorial Counter-Current, setting from Kast to West, between lats. 5° and 8° or 10° North, across the entire breadth of the Pacific Ocean. In an examination of the then existing data, it was found that this well-known Guinea Current was but an extension of this Cownter-Current, which might then be traced nearly over to the American coast.

In the much more extensive series of Current observations collected in the Meteorological Office, and arranged by Mr. R. Strachan, the character of this Current is fully established in accordance with the views expressed

* On Oceanic Currents, &c., by A. G. Findlay, in the Journal of the Royal Geogra-

in 1853. As the charts contained in that work* embrace a much wider range of observation than was before attainable, we shall quote on this Current, as on the other branches of the subject, the general remarks based on the results obtained for each month.

(264.) By a careful calculation of the Currents experienced by the ships cited in Maury's and Rennell's Charts, they appear to set with great regu- larity, and constantly to the South-Hastward. The experience of eighty- two ships for the year gives a mean direction and rate of 9:1 miles per day to BE. 34° S., for the offing of 350 miles off Cape Finisterre and the Northern part of Portugal. The average of the months is greater than this : - to 8.S.E. These, compared with the drift of Bottles, show that the latter must be affected by surface causes, as their rate of travelling is much less.t All these observations are integrated on the Chart of the North Atlantic Ocean, referred to previously.

(265.) We now give the remarks drawn up by Mr. Strachan on this Current in the work before quoted, first those for the annual mean, and then for each month in succession.

The North African Current. - lIf a line be traced from the Azores to Madeira, and thence to the African coast, in lat. 28° N. (Canary Islands), it will be seen that to the Northward, as far as lat. 40° N., the average general direction of the Current is to the S.H., at from 3 to 12 miles a day, the rate being strongest between long. 10° and 15° W. Hastward of the 10th meridian the direction becomes more Hasterly toward the Straits of Gibraltar, but counter-currents have been experienced off the coasts of Spain and Morocco. It is to be noticed that the resultant rate close to the coast of Portugal is only 1:4 mile a day, arising from the variation in direction of the observations here. South of Madeira the Current, between the coast and the 20th meridian, turns to the South, and then to S.S.W., down to lat. 10° N., its rates ranging from 3 to 13 miles per day. Between the meridians of 10° and 20° W., and the parallels of 30° and 10° N., this Current appears to slough off to the $.S.W., S.W., W.S.W., and finally merges with the Westerly drift of the North Equatorial Current about the meridian of 20° W., the rate being about 6 to 9 miles a day.

On the whole it does not appear that the waters of the North African Current mingle to a great extent with those of the Guinea Current. On the contrary, it would seem that they are finally forced towards the West by the superior strength of the Guinea Current. Even the portion of the Current which passes Eastward of the Cape Verde Islands does not appear

* Currents and Surface Temperature of the North Atlantic Ocean, from the Equator to lat. 40° N., for each month of the year.

+ Beane the set of the Current by Captain Becher's Bottle Chart, mentioned on page 295, we get the following : - Bottle No. 7 (drift 500 miles), 3-2 miles per day; 5-5 miles per day, giving an average of nearly 6 miles per day.

in general to mingle with the Guinea Current. The general tendency Northward, which the Guinea Current exhibits off Sierra Leone, must lead rather to the inference that some of the water of this Current finds its way into the Westerly Drift (North Equatorial Current), mingling with the receding North African Current about lat. 10° N.

Off the African coast, from 10° to 17° N., the Current is a variable one, at times setting to the Northward, fed by the Guinea Current, but more frequently to the Southward, fed by the North African Current. Here, therefore, the general rate comes out low, being from 3 to 6 miles, though the seasonal rates are much higher. Among the Cape Verde Islands the rate is also extremely trifling, and this is probably accounted for by the effect of tides upon a ship's course near the land, as sets in various direc- tions have been reported here.

January. - The North African Current, flowing to the Southward between Portugal and long. 18° W., acquires an Easterly tendency towards the Mediterranean Sea. After passing Madeira, it flows to the Westward of South, extending to long. 25° W. in the latitude of the Cape Verde Islands, where it merges into the Westerly Drift. The portion which passes between these islands and the continent merges into the Guinea Current about lat. 10° N. The daily rate of this Current is from 6 to 18 miles.

February. - The North African Current, between the parallels of 40° and 30° N., extends from the coast to long. 18° W. Here it appears to be fed by a drift from the W.N.W., which is traceable to long. 35° W., anda tendency towards the Mediterranean is apparent. The daily rate is from 9 to 22 miles. Southward, to the 20th parallel, observations are deficient, but between 20° and 10° N. the Current, though very feeble, is still per- - ceptible. Eastward of the Cape Verde Islands it tends towards the land while drifting onward to join the Guinea Current in lat. 10° N. Westward of these islands it soon becomes lost in the Westerly Drift. From the 20th to the 5th degrees of latitude the rate of this Current varies from 8 to 19 miles per day.

March. - The North African Current does not appear to have a decided Southerly set near the land as much as along the 20th meridian, where it travels 20 or 30 miles a day abreast Cape Verde. The Easterly tendency towards the Mediterranean is well marked at from 7 to 20 miles per day. To the North of the Canary Islands there is evidence of a counter Westerly 15° W., a North-Westerly set has at times been experienced of 17 to 23 miles daily, considerably stronger than the South-Hasterly sets, which are reported there in this month. From 20° to 10° N., and 25° to 27° W,, the Currents appear to be uncertain, but to the Westward the Westerly Drift seems established.

April. - The North African Current exhibits more decided southing than in March, but the inset to the Mediterranean is scarcely perceptible. It extends about 10° from the land, from lat. 40° to 8° N., where it joins the Guinea Current on the right, and the Westerly Drift on the left,

May. - The tendency of the Current towards the Mediterranean is still evident, but the flow Southward is more decided than in April. From 40° N. to the Canary Islands the rate is from 7 to 21 miles. This Current

extends generally about 10° from the land. South of the Canary Islands the Current tends towards the West. It mingles with the Guinea Current about lat. 7° N., and with the Westerly Drift along the meridian of 25° W., reaching as far South as 7° N. As a South-Westerly current its rate is about 12 miles.

June. - The North African Current can be traced from lat. 40° to 9° N. It still sends an Easterly current towards the Mediterranean, at a rate of 6 to 18 miles. Between the Canary and Cape Verde Islands its direction is South-Westerly, but the stream is feeble, the rate being from 6 to 18 miles. It does not pass between the Cape Verde Islands and the coast, but lies entirely to the Westward of these islands, where it soon becomes merged in the Westerly Drift. Between lats. 20° and 9° N., longs. 23° and 30° W., it is stronger than elsewhere, its velocity ranging from 8 to 19 miles per day.

In July the Current appears to be feeble and unsettled, and the indraught to the Mediterranean is barely traceable.

In August it does not seem that the Current is well maintained, nor is there decided evidence of a set towards the Mediterranean; however, the observations in this month are deficient.

September. - The North African Current can be traced to the Cape Verde Islands, but it is feeble throughout its course. Very little tendency is apparent towards the Mediterrnean ; indeed, the direction of the set is sometimes opposite. ;

In October the Current reaches to lat. 10° N., but it is feeble and irregular, being best defined close to the coast.

In November the Current is str onger and more regular than in September and October. Off Portugal its set is E.S.E. » and rate about 12 miles. It

can be traced as far South as lat. 9° N.

In December the North African Current has become a steady flow, and can be traced at times from lat. 40° N. to 10° N. In the region of the Cape Verde Islands it loses force, and becomes less regular.

(266.) Im addition to these remarks we give, as in previous editions, the particulars of various Bottles and other experiments, which are very in- teresting, and will be serviceable in estimates of what amount of Current may be expected in this part of the voyage.

Toward the Bay of Biscay. - The ship Carshalton Park, Captain J. S. Park, on returning from Jamaica to London, July, 1824, in lat. 48°, long. 18°, got into a stream setting to the Southward, and which thence operated so strongly against the ship, that some difficulty was found in getting sufficiently far to the Northward for a good Channel track. The wind shifted suddenly from 8.W. to North; the vessel immediately hauled up E. by S.; and although the weather was fine, and the water quite smooth, she made no better than a true E. by N. course.*

South-Easterly Current off Channel Soundings. - In August, 1826, Captain Living- ston, in the Jane, between lat. 48° 53', long. 16° 7', and Cape Clear, had a set of

* The same ship, on the 10th of July, was on Channel soundings, the latitude by meridian altitude of the sun, 48° 53'; the longitude, by chronometer and lunar, 9° 44' and 9° 56' respectively, ''kept the ship EK. 4 S. and generally Hast till 11.51 p.m., when, by the moon's meridian altitude, it was found that the latitude was 49° 21'. We had

1° 14' S. and 1° 54' E. So that in four days the vessel was set, by a counter-current, 74 miles South and 65 miles East, or nearly S. 41° E., about 99 miles; equal to a daily average of 24? miles.

Off the Coast of Portugal. - A Bottle from the brig Freeland, Captain T. Midgley was picked up close to the shore, off the Harbour of Vigo, on March 1st following, having traversed, in a true E. } N. direction, about 240 miles.

St. George's Channel to Cape St. Vincent. - On August 14th, 1823, Captain Living- ston, in the sloop Favourite, on his passage from Liverpool to Gibraltar, took his departure from the Smalls Lighthouse, and thence he regularly made observations on the Current, &c., so far as adverse weather permitted. On the 23rd he had arrived on the parallel of 46° 23'; previously to which the course seems to have been materially affected by the Tide, but here the differences amounted to 51' 55" Southerly, and only 4' 39" Northerly. From lat. 46° 23', on August 23rd, to lat. 36° 52', on August 31st, the Current invariably predominated to the Southward, and between these parallels amounted to 89 miles in the eight days.

At 4" 53™ of August 31st, with Cape St. Vincent bearing true North, an excellent meridian altitude of the planet Saturn gave lat. 36° 52'8". The total Southing to this point gave 2° 18', and the difference of longitude between dead-reckoning and that by landfall gave 1° 42' 7" of Easting.

In the brig Friends, of Glasgow, August 24th, 1820, Captain Livingston states - "The current set us round Cape St. Vincent without our having seen the cape, though we steered courses for the purpose of seeing it, and we were looking out for it, when I got a lunar, and ascertained thes we were then past it. Immediately after this the sea became smooth, being broken off by the cape."

Between Cape Finisterre and the Azores, the general drift of the surface of the sea appears to be to the South-Eastward; varying, however, to the East and West, and even to the Northward, as the winds operate, either one way or the other, more especially during winter, as already noticed.

H.M.S. Pactolus, in May, 1816, experienced a current South a little East, at the average rate of 30 miles a day, from the English Channel to St. Michael's.

Captain Charles Hare, in the brig Ward, from New Brunswick, September, 1823, with Westerly winds, which had prevailed for fourteen days, between lat. 43° 40'

Between Portugal and the Western Islands. - Captain George Cheveley, in June, of a mile an hour.

The Current along the Coast of Portugal appears to set nearly in the direction of that coast. On the 25th of October, 1810, a gunboat for the service of Cadiz, being in tow of the Rebuff gun brig, broke adrift in a gale of wind, in lat. 39° 44', long. 9° 38' W. On the 19th of November following, his Majesty's sloop of war Colum- bine, when cruizing 8 or 9 miles to the Westward of Cadiz Lighthouse, observed a gunboat to leeward, which proved to be the identical boat that twenty-five days before had broken adrift from the Rebuff. The distance traversed by the boat was about 350 miles, or 14 miles a day, chiefly by the Current, the wind in the mean- time being so various as nearly to render the drift negative, or, if anything, against the set of the Current.

On the Currents setting toward the Bay of Biscay and the Strait of Gibraltar, Captain, afterward Admiral, Sir Erasmus Gower made observations in five passages gone, during this interval of 114 51™, 68 miles by the log, carefully attended to, in smooth water. Now, allowing 24 points of variation, we ought to have made 26' of northing ; whereas, in point of fact, we made 13' only."

Influenced, probably, by the Channel ebb, the Current appeared also to have a ten- 'dency to the West.

to Madeira, from which he concluded the most general direction to be to the $.E., and the mean yelocity about 11 miles in every 150 miles.*

In proceeding to Tenerife, Sir Erasmus Gower observed a constant Current set- ting to the Southward at the rate of a mile an hour; equal to 22 miles in the distance between Madeira and that island.

Captain Mackintosh, of the Hindostan, who had made twenty passages in this route, generally experienced a Current from the 39th degree of latitude to that of the Canaries. Jn this part of the ocean he generally found, from repeated and accurate observations, that this Current sets to the E.S.E. He found it strongest opposite to the entrance into the Mediterranean or Strait of Gibraltar; and, in one voyage, the Current was computed, by his chronometer, to set about 40 miles per day. This current inclines more Southerly as it approaches the Canaries. It strikes on the coast of Morocco, and takes, about Cape Boiador, a different direc- tion. Nearly inshore, from an indefinite point, one part of the stream sets North- ward toward the Strait of Gibraltar, and the other part sets to the Southward.

M. le Baron Roussin, in the corvette Bayadére, bound from Rochefort to Brasil, in February, 1819, after passing Cape Finisterre, found the prevailing Winds from noon to noon, and Currents, as follow : -

Latitude. Longitude. Winds. Currents.

But on arriving at the Canaries, with the wind North and N.E., the Current had changed.

* The effect of a Current setting to the South-Eastward, and the necessity of a com- petent knowledge of Currents in general, cannot in any way be more forcibly shown than by noticing the melancholy catastrophe of His Majesty's ship Apollo, Captain J. W. T. Dixon, and the merchant ships under her convoy, on the 2nd of April, 1804. The Apollo, with sixty-nine ships for the West Indies, sailed from the Cove of Cork on the 26th of March. With a fair wind, blowing strong, they steered about W.S.W. until the 31st, when the wind changed more to the Westward. At noon, on the Ist of April, latitude observed, 40° 51' N., longitude, by account, 12° 29'. At 8 p.m. the wind shifted to S.W., and increased to a gale, with a heavy sea. The convoy stood to the §.S.E., and, at half-past three next morning, struck on the coast of Portugal, in about 40° 22' N., 9 miles to the Northward of Cape Mondego. Captain Dixon, and about sixty men of the Ayolio, perished in their endeavours to reach the shore; the other part of the crew remained two days clinging to a fixed part of the wreck, without nourishment. About forty sail of merchantmen were wrecked about the same time; some sank with all their crews, and most of them lost several men. This lamentable event was attributed to want of chronometric observations, and the consequent ignorance of the set of the Current, which must certainly have been very strong.

"The immediate cause of the loss of so many of the Aypollo's convoy appears to have been the blind confidence with which the commanders followed their commodore; either keeping no reckoning themselves, or believing his more accurate than their own. Several ships were saved by leaving the convoy, and it is said that the commander of a Clyde ship warned the commodore of his danger in time to have avoided it." - 4. L.

A more recent example of the fatal effects of this current being disregarded is the loss of the Anchor Line steamer Rowmania. On the night of October 28th, 1892, she sud- denly ran aground near Peniche, on the coast of Portugal, only two passengers and six lascars saving their lives out of a total complement of 112 crew and passengers.

On the course of the same vessel, from Brest to Brasil, in October, 1821, the §.. 15° E., 20 miles; on the three following days, nearly in the same direction, but long. 13° 16' 20', it had set 32 miles to the S.W., or in a direction nearly parallel with the shore.

At about 222 miles W. 4 S. from Cape Mondego, on the 9th of June, 1799, M. de Humboldt, in the sloop Pizarro, was on his voyage to the West Indies; and, on this day, in lat. 39° 50', long. 13° 50', he says that they began to feel the effects of the Current setting toward the Strait of Gibraltar, &c. From the parallel of 37° to that of 30°, the vessel was sometimes carried, in twenty-four hours, from 18 to 26 miles to the Eastward. The direction of the Current was, at first, E. by S8.; but nearer the strait it became due East, and it assumed a more Southerly direc- tion on the passage towards Tenerife. ''Several pilots, who frequent the Canary Islands, have found themselves on the coast of Lanzarote, when they expected to make good their landing on Tenerife."

Don Vicente Tofino sailed on the 27th of April, 1785, in the Luca, from Cadiz, for Mogador, and on the lst of May, before mid-day, arrived at the last-named port. On the 5th he sailed from it, and on the morning of the 8th anchored again in Cadiz. On his voyage out, he found that the Current, in four days, had set him 214 miles S. 18° E., and on his return §. 49° W., 39 miles. This variation of the Current shows, that the waters throughout all this extent do not always run to the S.E., but that they vary, with the line of coast, to the South- Westward also.

H.M.S. Pique was once set to the §.E., 98 miles in five days, between Cape Finisterre and Madeira. H.M.S. Raleigh, August, 1826, found the Current from off Cape St. Mary, toward the Strait, to set W. 34° S., 26 miles in the twenty-four

(267.) The following observations on the Currents between the Canary and Cape Verde Islands, are selected from Commander Maury's " Sailing Directions'" 1859, vol. ii. The experience of all the ships whose logs are there recorded, is nearly unanimous in stating the Southerly and Easterly drift. Of course, the vibration of the Trade Winds with the seasons has much to do with the Southern limit of this Southerly set, as will be seen below : -

Ship Jenny Pitts, Captain J. L. Snow, December 27th, 1853, lat. 30° 3' N., long.

Ship Margaret Mitchell, Captain T. Jameson, January 11th, 1854, lat. 30° 16' N.,

Ship Romance of the Sea, Captain W. W. Henry, February 18th, 1855, lat.

Ship Gloriana, Captain Henry Toynbee, from London to Sydney, April 22nd,

12 miles South.

ship was at this time in the N.E. Trades, which have during the summer reached to the higher latitude.

(268.) Mr. James Grey Jackson, in his valuable '' Account of the Empire of Morocco," stated that the coast, between the latitude of 20° and 32° North, is a desert country, interspersed with immense hills of loose sand, which are, from time to time, driven by the wind into different forms, and so impregnate the air with sand, for many miles out to sea, as to give the atmosphere an appearance of hazy weather. Navigators, not aware of the circumstance, never suspect, during such appearances, that they are near land, until they discover the breakers on the coast, which is, in some parts, so extremely flat, that a person may walk a mile into the sea without being over the knees; so that ships strike when at a con- siderable distance from the beach. Added to this, there is a current, which sets in from the West towards Africa with inconceivable force and rapidity, with which the navigator being generally unacquainted, he loses his reckoning, and, in the course of a night, perhaps, when he expects to clear the African coast, in his passage Southward, he is alarmed with the appearance of shoal water; and, before he has time to recover himself, finds his ship aground on a desert shore, where neither habitation nor human being is visible. In this state his fears are soon in- creased by a persuasion that he must either perish in fighting a horde of wild Arabs, or submit to become their captive; for soon after a ship strikes, some wandering Arabs, strolling from their duar in the desert, perceive the masts from the sand-hills ; and, without coming to the shore, repair to their horde, perhaps 30 or 40 miles off, to apprise them of the wreck, when they immediately assemble, arming themselves with daggers, guns, and cudgels. Sometimes two or three days or more elapse before they make their appearance on the coast, where they await the usual alternative of the crew either delivering themselves up, rather than perish with hunger, or throwing themselves into the sea.t

* London, quarto, 1809. See, also, the affecting '"' Narrative of the Shipwreck and Captivity of M. de Brisson,' in 1787; and that of Robert Adams, wrecked in the American ship Charles, John Horton, master, 1810. This subject is noticed more par- ticularly in the description of the coasts of Africa, hereafter.

+ Even at the present time, as more fully described hereafter, it is necessary to remember the merciless character of these Arabs. On August 20th, 1892, the Spanish trading cutter Icod, when anchored at Parchel, near Cape Bojador, was boarded and looted by Moorish corsairs, who carried off eleven of the crew as prisoners, the other five escaping in the cutter's boat.

The Elza, commanded by John Searchwell, sailed from Cork for Rio Janeiro with settlers, on the 12th of August, 1627, and ran ashore on the coast of Africa, during a fog, on the 25th of the same month. Whilst making signals of distress, three fishing boats from Canary came to her assistance, and succeeded in saving all the lives on board, consisting of 18 mariners, 244 men, 46 women, and 42 children ; in all, 350 persons, who arrived at Canary on the 3rd of September.

About the end of October, in the same year, the Olymphe, trom Havre fot Buenos Ayres, with colonists, was cast away on the same part of the African coast. The passengers, about 300 in number, consisting of French, English, Germans, and Swiss, were taken from the shore, saved from captivity by Canarian fishing-boats, and conveyed to the Grand Canary, where they were landed on the 7th of November. Such have been the effects of the Current!

(269.) The ship Montezuma, of Liverpool, Knubly, master, sailed on the 26th of October, 1810, from Brazil, but was wrecked on the 28rd of the next month, at 3 am., on the African coast, somewhere between Capes Noon and Bojador. Among the crew, who were taken and sold by the Arabs, was Alexander Scott, an apprentice. This person was detained in the country for nearly six years; and a very interesting account of his captivity, drawn up by Dr. Traill, with geogra- phical observations on his routes, and remarks on the Currents which produced the catastrophe, by Major Rennell, were given in the fourth volume of the '" Edin- burgh Philosophical Journal." As these remarks give a very clear notion of the movement of the waters, derived from observation, we repeat them as heretofore.

(270). Major Rennell, in 1819, remarks on the Currents between Cape Finisterre and the Canary Islands : - ''I should consider myself highly culpable if I neglected to state, by way of caution to navigators, the result of my inquiries respecting the Currents which appear to have caused the shipwreck of the Montezwma, and of a great number of other ships of our own and other nations, on the Western coast of Barbary, having examined a multitude of journals of ships that have sailed in that track, with time- keepers on board, and which have also, when opportunities presented themselves, had their rate checked by celestial observations.

"The general result is, that navigators who depart from the parallel of the Southern part of the Bay of Biscay (or say 45°), and sail in the usual track Southward, will be assailed first by a S.#. current, and then by an Easterly one, until they have passed the parallel of Cape Finisterre, when the Current will again turn to the South of East, and gradually become a S.E. Current, till, having passed Cape St. Vincent, it becomes Easterly again, owing, no doubt, to the indraught of the Strait of Gibraltar; and this Easterly Current is pretty general across the mouth of the bay between Cape St. Vincent and Cape Cantin.

'Beyond this bay (which may be termed the funnel, of which the Strait itself is the spout) the Current again becomes 8.E., or rather more Southerly (as it is more Easterly toward Cape Finisterre), and continues as far as the parallel of 25°, and is, moreover, far beyond Madeira West- ward ; that is, at least 390 miles from the coast of Africa, beyond which a S.W. Current takes place, owing to the operation of the N.E. Trade Wind.

«The rate of motion of this Current varies very considerably at different times; that is, from 12 to 20 or more miles in 24 hours. - I consider 16 miles as rather below the mean rate. I have one example of 140 miles in eight days, in one of His Majesty's ships, equal to 174 miles per day; and, i»

another, of only 12 miles; and in a very well kept East India ship's journal, 170 miles in nine days to Madeira, or 19 miles per day. The direction of the stream likewise varies, but is commonly more toward the South than the East, after passing the mouth of the Strait.

'' Near the coasts of Spain and Portugal, commonly called the Wall, the Current is always very much Southerly, owing, perhaps, to the falling in, obliquely on the shore, of the great mass of water brought by the S.E. Current ; which can run off only toward the South, and round Cape St. Vincent toward the Strait's mouth. Amongst the Canary Islands, and between them and the coast of Barbary, the Currents are less regular.

'Tt may be taken for granted that the whole surface of that part of the Atlantic Ocean, from the parallel of 40° to 45° at least, and to 300 to 400 miles off shore, is in motion toward the mouth of the Strait of Gibraltar.

" According to what has been said, in the course of the above remarks, it must be expected that a ship, sailing in the usual track to Madeira or the Canaries, will be carried to the South-Hastward, at the rate of 16 miles per day; that is, even if she has a fair wind, she will be carried by the Current 150 or 160 miles to the South-Eastward, in the course of a voyage to Madeira or the Canaries ; and, consequently, on a S.H. by S. course, will be carried 80 or 90 miles to the Eastward of her intended port. If we suppose a S.H. course, the error in easting will be no less than 109 miles; which distance, if they are bound to Tenerife, would carry them to Allegranza or Forteventura ; and, if intending to make Allegranza, would place them on shore on the coast of Barbary. The French and Spaniards report that their ships have often made Allegranza when they supposed themselves on the line toward Tenerife. It must be added that, if a ship had a long passage, the error would be greater in proportion, and might possibly amount to 200 miles of easting.

"It would seem advisable, therefore, that every ship going to the Canaries, or intending to sail between those islands and the mainland of » Africa, if without timekeepers, should, to every day's reckoning, add ten miles of easting. This would, in the first instance, prevent them from decewing themselves as they went forward ; in like manner, as it is better to set a clock forward at once, than to charge one's memory continually with its being too slow. Ten miles does not seem too much as a cautionary measure, as a ship has very lately been carried 99 miles to the Hast in eight days in that track. What would not have been the error had she had even a moderately long passage ?"'

The preceding description of the Currents between the English Channel and the Canary Islands was corroborated, 1826, by Captain R. H. N ewby, in the Napoleon schooner, which left Dartmouth on the 21st of July, and was set to the Eastward of her reckoning, while crossing the Bay of Biscay, 1° 21' of longitude in 48 hours. On Monday, the 25th of the same month, the entrance of Ribadeo bore S.W. by compass, about 15 miles, and the vessel was then in about 6° 55' W.

The effect of the Easterly Current was proved by the bearings of a re- markable mountain inland, and some whitish cliffs on the shore; and Captain Newby says, the schooner was setting to the Eastward as fasi as

he had noticed a ship to lose ground to the Eastward while standing in- shore of Beachy Head during a strong flood tide and moderate Westerly breeze. At about 5 p.m. the wind veered to the N.E., and even then, although the vessel was going at the rate of 34 knots through the water, she made very little way to the Westward till toward sun-down, when the breeze freshened to 7 or 8 knots. During the night, passed Cape Ortegal; and the next morning, at 6 a.m., the light tower at the entrance of Coruiia bore South.

Upon going over the two days' work, July 27th and 28th, it appeared that, instead of passing, as supposed, to the Westward of Madeira, the Napoleon was actually out of sight of the island to the Hastward ; and had the vessel been involved in fog, or have been bound to Lanzarote or Fuerteventura, and steering, by reckoning, a fair course for them, the consequence must have been that she must have fallen into broken water when least expected, or have grounded on the mainland, somewhere between Cape Ghir and Cape Noon, and property, if not life, would have been lost.

(271.) Coasts of Spain and Portugal. - Besides the Northern branch of the Atlantic Hasterly drift which sets into the Bay of Biscay, there is a Southern branch, which from Cape Ortegal turns gradually to the 8.H. and Southward along the coast, and, after passing Cape St. Vincent, sets Hastward towards the Strait of Gibraltar. This is in ordinary weather, but with strong Westerly winds it sets towards the land, and this unsus- pected drift has led to the loss of numerous vessels, as detailed previously on page 317. With strong Southerly winds, the current may be found setting Northward.

Due attention to the soundings, when the position is uncertain, should keep a vessel clear of danger along this coast, bearing in mind the Hasterly onshore current usually accompanying N.W. and Westerly winds, and the effects of the heave of the sea affecting the steering.

(272.) The following remarks on the Currents on the Western coast of the Spanish Peninsula are given in the Anuario Hidrografico for 1867 : -

On the Western shore of the Peninsula the Currents are strong, and in its immediate neighbourhood run from South to North, and North to South, according to the prevailing wind. But in the offing they incline to the N.E. or 8.E., according as the wind may be S.W. or N.W. Against these onshore winds vessels must therefore take precaution, for if the S.W. wind is blowing, or even the N.W. also, the vessel will drift to the shore. Expe- rience has shown that allowance must be made for drift by steering more Westerly courses than the lay of the coast would require to keep clear of it, especially when it is blowing hard.

It is observed on the coast of Galicia, and the same would naturally occur on the coast of Portugal, that, on one or even two days previous to a gale, the Current sets towards that point of the horizon from which it will eventually come; that is, when the Current sets to the South without any apparent cause, the Vendaval (144) will come in a gale, and a similar result follows when the Current sets to the North. So that the fishermen, who have most to do with allowing for Currents, know very well by them when a N.E. or S.W. wind is about to set in.

The Current generally produced by the wind sets to the N.E. and North, when that is from any point between South and West, and it sets to the South when the wind is anywhere between West and East from the North- ward. In winter, the Current sets mostly from some point between North and East, and in summer from some one between North and West; and its hourly rate is about 2 miles, and even more, with a strong Vendaval.

The navigator who finds himself off Cape Finisterre with a Vendaval to beat against, must be careful of the shore in bad weather, for he will be drifted insensibly to leeward until he has passed Cape Prior.

With respect to ships off Cape St. Vincent, bound towards Cape Finisterre with fresh N.H. winds, they will find enough to do, to overcome the Current they will meet with along the coast. And with fresh N.W. or S.W. winds there is also a rise in the level of the sea, in all the estuaries and ports of the Peninsula, the reverse of what takes place at Cadiz and in the Bay of Biscay with N.E. winds.

(273.) Tue Baron Roussrin's Remarks ON THE CURRENTS BETWEEN Care Bosapor AND THE IsuES DE Los.

The general Currents on the African coast, between Cape Bojador and the Isles de Los, with the exception of some places subject to a more or less regular tide, are uniform during the eight months which comprise the fine season. They follow exactly the trend of the coast from North to

From Cape Bojador to the Bay of St. Cyprian (lat. 22° 20') they there- fore set to the S.S.W.; from that bay to Cape Blanco, and along the whole extent of the Bank of Arguin to its Western point, which is in the parallel of 20° 6' 20" N., they set S. by W. To the Southward or this point the waters, being no longer guided by the edge of the bank, which turns abruptly to the S.H., do not follow in a body, within a certain space, any fixed or determined direction. One part of their mass experiences a number. of irregular windings, until, finding itself in the active body of the general Current, which left the bank at its most salient point, it rejoins it, and is carried on as before.

In the vicinity of Tanit Bay, in the parallel of 19°10' N., it again resumes its former direction, and follows the trend of the coast, thus setting to the Southward as far as near Portandik, and from thence S.S.W. to the Marigot of Musquitos. It then sets S. 4 W. till abreast of the Bar of the Senegal, where, in a space of 12 miles in circumference, it is disturbed by the stream of that river. This stream is so strong as to oblige vessels at the anchorage off the bar to trend to it, in spite of the strongest winds. The Current, joined by the waters ot the senegal, pursues its course along the coast, which trends to the 8.W., observing a very gentle curve, which forms the Bay of Yof, and which terminates at Cape Verde. The strong Currents hitherto pretended to set into the Bay of Yof are, therefore, merely chimerical. Cape Verde being the most Western point of Africa, and hence forming an obstruction to the general direction of the waters which flow along that coast, must occasion a great variety of Currents in

its vicinity. This is,in fact, what takes place, and it would, therefore, be difficult to define a particular one. This only appears certain: vessels passing in sight of Cape Verde are not carried on it, as is generally sup- posed ; but, on the contrary, they are swept off by the prevailing tendency which the waters have to flow to seaward. In running close to Almadie Rocks, this repulsion is sensibly felt during the eight months which I have mentioned. It appears that the Current rushes between the rocks, and spreads itself in different directions.

Immediately to the Southward of Cape Verde the Current is almost imper- ceptible, and it is scarcely possible to assign any particular direction to it as far as Cape Naze. The whole of the coast lying between this cape and ' Cape Manuel forms a well defined bay, totally free from Current, and in which there is not a single river. The same is observed with respect to the roadstead of Goree, although, according to the observations of Mr. Adanson, a regular tide exists there, with a rise and fall of 24 feet. In the offing of Cape Verde the Current has been always found to set to the Southward. From Cape Naze it again follows the direction of the coast, interrupted only at the mouths of the principal rivers, which lie between this cape and Cape Roxo. From this point, localities of a very different nature produce | particular effects in the Current. The Archipelago of the Bissagos here succeeds the straight coast which extends to the Northward. Large rivers empty themselves amongst these islands, forming various channels, more or less encumbered with sand-banks. These obstacles cause a variety of Currents, which will be explained when treating on the Bissagos.

Strength of the General Current. - The rate of the general Current on the African coast, deduced from numerous observations, has never exceeded 14 mile per hour on the coast itself, and on the outer edge of the banks; and more frequently it has been found from seven to nine-tenths of a mile. This is diminished one-third, and frequently one-half, at a distance of 12 miles from the coast. Should a sailing vessel have run past her port, there is no fear of her not stemming this Current, and, by long boards, easily regaining her destination.

In the Rainy Season, which is from the commencement of June to the end of October, as the wind blows from various directions, the Currents are no longer regular, and it is impossible to establish any positive law respecting them; but, even under these circumstances, their strength 1s not so great but that it may be surmounted.

157, and in the diagram illustrating the Best Monthly Routes Across the Equator, it is shown, that between the N.E. and §.H. Trade Winds there is a Belt of Calms and Variable Winds, which, on the African coast, assume the character of monsoons, as, during the summer months espe- cially, the wind blows more or less toward the African coast.

In the Currents there appears to be an analogous system, as there is an Easterly Current flowing with considerable velocity Eastward, in an oppo- site direction to the great Equatorial Drifts on either side of it. Its existence and character along the Guinea Coast has been long known. It was formeriy thought to be a continuation of that Current which we have just described as passing Southward from Western Europe, but later inves- tigations seem to point to the fact that it is a flowing back of the waters heaped up to the Westward by the prevalent winds. In tracing the Currents of the Pacific Ocean,* we find that there exists a precisely similar Current in that great ocean setting into the Bay of Panama, in the same latitude. This Current is traced very far to the Westward - in fact, nearly across the ocean.f

(275.) Commencing with the ordinary Westernmost part traversed by vessels crossing the Equator, we select from Commander Maury's Sailing Directions the following facts : -

Captain H. T. Walter, barque Phantom, says : - In July, 1853, between lat. 5° and 8° N., and about long. 36° and 38° W., the Current set us fast to the Eastward. Again, in August, 1854, about the same latitude and longitude, the Current set us 110 miles N.N.E. in three days. Capt. Millet writes : - December 25, 1855, lat. 4° N., long. 29° W., have experienced an Easterly Current these last two days. I have always noticed such along these latitudes, sometimes more to the Northward than this, and in lat. 1° N., and long. 44°.

We have here examples at opposite seasons of this Current in the Western crossing of the Atlantic.

Ship James Brown, Captain C. W. Kerlin, January 12, 1856, lat. 8° 43' N., long. miles Easterly. Crossed the Equator on the 16th, and experienced no Westerly

Ship Margaret Mitchell, Captain T. Jameson, January 23, 1854, lat. 4° 36' N.,

* See Directory for the North Pacific Ocean, by A. G. Findlay, and also Journal ot the Royal Geographical Society, vol. xxiii., pp. 222, &c., as before quoted on page 312.

+ The non-continuity of this Guinea Current with that which flows Southward from Portugal and N.W. Africa, the North African Current, was demonstrated by the author many years ago, and its analogy with the Equatorial Counter-Current in the Pacific, and also with a periodical Easterly Current in the Indian Ocean.

Current setting to Eastward, though the ship was steering S. by W. 4 W.

to the Northward than usual).

per hour.

Brig Director, Captain Skinner, writes : - '' You perceive that I had a strong Current between lat. 7° and 5° N., on September 7 - 10. Not getting an observa- tion for four days, I found the brig nearly 38° farther Hast than I expected; whether I had it in one, two, three, or on the fourth day, I cannot say, but suppose I had some each day. I was speaking with several captains, and they say that they have always found a strong Current about them going to the Eastward."

Captain Maury adds : - '' An Eastwardly Current is often found North of the Line in summer and fall; and at those seasons it may be counted on with some degree of certainty." (This refers to the Western crossing of the Equator recom- mended by Captain Maury).

Ship Flying Dutchman, Captain A. Hubbard, October 12, 1854, lat. 8° 55' N., long. 40° 52' W. - ''I notice for the last two days (from lat. 11° 28') the lines of agitated water, previously noticed, appear all to run nearly E.N.K. and W.S.W., and follow each other at regular intervals of some 4 or 5 miles; the motion of the waves running at right angles to the line of rip. October 14, lat. 6° 46' N., long. East, 14 knot. One year ago last July I experienced a similar Current in the same latitude, but some 10° farther East. October 16th, lat. 6° 49' N., long. long. 33° 33' W., East, Southerly, 14 knot, slight current rips. 20th, no Current. All these days generally calm, or light variable airs."

Ship Robert Patten, Captain G. 8. Paine, October 30, 1856, lat. 10° 14'N., long. 88° 50' W., '' tremendous tide-rips, the strongest I ever saw." October 31, lat,

Schooner Thomas A. Ward, Captain J. D. Hoff, October 30, 1855, lat. 6° 5' N., long. 27° 40' W., the last twenty-four hours have been the most calm that I ever saw, not a breath from any quarter, and a terrible rolling sea. We drifted S.E.

The foregoing are the principal notices of the Easterly Current as re- corded in Captain Maury's Sailing Directions, vol. ii., 1859, and, in fact, is nearly all that is mentioned on Currents, as but very few, if any, of the abstract logs quoted in that work mentioned any Westerly or other Currents, the only exception being that in some very few cases a Northerly set is noticed. Besides this, there is frequent mention of current or tide-rips, often of a very formidable character, denoting great activity and change in the Currents of this troublesome region.

(276.) Some records of more recent Bottles are given below : -

A Bottle from the ship Douro, in long. 31° 5' W., on the Equator, June 28rd, 1880, was picked up on the beach near the entrance of the. River Niger, in lat. 4° 43' N., long. 6° 35' K., in April, 1881. The least distance traversed was about 2,300 miles, in 10 months. (See Drift diagram, page 297).

A Bottle from the ship Patriarch, in lat. 2° 46' N., long. 22° 3' W., December 11th, 1884, was picked up on the beach near Grand Popo, in May, 1885, having drifted about 1,200 miles in five months. (See Drift diagram).

Four Bottles from the steamer Buccaneer : - One, in lat. 6° 40' N., long. 12°82' W., January 6th, 1886, was washed ashore, March 5th, 1886, 10 miles from Addah,

drifted 690 miles in 53 days, averaging 13 miles a day.

drifted 372 miles in 59 days, at the rate of 6°3 miles a day. (See diagram).

days, or only 1°6 mile a day. (See Drift diagram).

The first two were thrown overboard to the West of Cape Palmas, and were carried very rapidly to the Eastward. The third was also thrown over to the Westward of Cape Palmas, but much farther off shore, and in the month of March. It was drifted right across the routes of the first two, and was cast up on the Kroo coast. Had the same current prevailed in March as did in January, on arriving in the track of these it ought to have been carried, like them, into the Bight; instead of this, it never even passed Cape Palmas. The fourth was thrown over between the Gaboon River and St. Thomé, and drifted very slowly in a North-Easterly direction, and stranded near Cameroon River, having required 147 days to make good a distance of 230 miles. No doubt it covered a great deal more ground, being drifted backwards and forwards by the very conflicting currents of this region. J

(277.) One of the most remarkable examples of this Easterly Current recorded, and one which unmistakably demonstrates its existence and activity, was encountered by John Alexander Mann, Hsq., F.R.G.S. and F.R.A.S.* He left Cayenne in French Guayana, in the brigantine Monte Christo, 120 tons, bound for Paranahyba, on July 26th, 1862, the day of the new moon; the wind blowing from the Kast. A direct Northerly course was steered until the 30th, when the ship was in 7° N., and the. log, by dead reckoning, was the same as Cayenne, 7.e. 52° 14', On August 7th, spoke the Austrian brig Rarita, which gave longitude 27° 14'; that of the dead reckoning of the Monte Christo gave 42° 14', so that the vessel had been drifted nine hundred miles to the Eastward, and for eight consecutive days she had been drifted 32 knots an hour to the H.S.H. There was a great doubt as to the accuracy of the longitude, but at noon of the 15th, in lat. 0° 45' S., they spoke a Dutch brig, which gave the longitude as 27° 8', while the D.R. placed them in 44° 0', which, com- pared with the position on the 7th, shows that they were drifted 120 miles farther to the Eastward. In fact, had the ship been left to the Current, it would have soon reached the African coast, having drifted

Throughout the remainder of the voyage, which lasted 14 days longer, the same Current was experienced. The captain of the Loyal, which arrived some days after, abandoned his chronometer from the same cause, believing it to be out of order. Afterwards, in sailing from Surinam to Cayenne, in the Alecton, French man-of-war steamer, Mr. Mann met with the same phenomenon.

(278.) These facts are very important, in connection with the Westerly crossing of the Equator, which has been strenuously advocated, and the influence of this powerful Current, which appears to have much constancy during the Northern summer months, may have much to do with the readiness with which vessels, having reached too far to the Westward, contrive to weather the Hastern extremity of Brasil. This will be adverted to hereafter.

(279.) The Kasterly Current thus passing across the Atlantic strikes the coast of Africa about Sierra Leone and the coast of Liberia. Of course, when near the shore, it assumes its direction to the S.E., and runs with great velocity. As is shown by the Chart of the Currents, at page 295, its mean annual velocity is between 14:1 miles and 26°5 miles per day, strongest in the summer months.

Its mean direction off Cape Palmas and Cape Coast Castle is E. 12° N., and its calculated velocity from Major Rennell's and Captain Maury's observations is - for January, 17°4 miles to 27°6 miles; February, 26 miles June, 30 miles; July, 18:2 miles; August, 15°7 miles to 26-4 miles per day. These are from the records of 75 observations.

(280.) Its Southern edge appears to be in about 24° to 2° N. up to the head of the Bight, and as the Southern streams set in an opposite direction, they are serviceable in making a return passage as presently explained.

* See Proceedings of the Royal Geographioal Society, Vol. VII., 1863, pages 50, 51,

The temperature of the Guinea Current is high, and demonstrates its Equatorial origin, although the branch of it which comes from the North- ward past Cape Verde has probably a lower temperature as coming from a higher latitude. The Equatorial Current to the Southward of the Guinea Current is also of a lower temperature, coming direct along the African coast from the Southern Polar regions. The mean summer tem- perature is about 78°, but in our winter and autumn months it is higher, being from 82:6° to 83° as a mean, and sometimes it is found higher than

(281.) H.M.S. Challenger, in crossing this Current, August 10th to 21st, 1873, made the following observations on the Temperature of the sea at different depths. From the Cape Verde Islands, 300 miles West of Cape Verde, her track was in a general South-Hasterly direction for 88 miles to & position 150 miles §.5.W. of Sierra Leone; thence, in the next two days, she proceeded to a position 160 miles to the 8.S.W., or 310 miles from Sierra Leone.

Temperature Observations, in Degrees (Fahrenheit), by H.M.S. Challenger, while crossing the Guinea Current, in August, 1878.

a eee Se GaN es Pad. eno ie ser Ni G8ehroGis 6Rwnenme BRERA 55 Se ee ee ay Mea am partes yey ae NR ala 5. P1000: 43 EEE TUT cay ors cad agers ol hers (cg gree tad ene Ween (care ea Bre

The above Table, it must be remembered, refers to the time of year when the Guinea Current is at its greatest power. Subsequently, in returning home, the Challenger, in the passage from Ascension to the Cape Verdes, in April, 1876, found the surface temperature in lat. 2° 30' S. of Cape Mesurado, the temperature was 83° on the surface, in the same position in which a temperature of 78° only was found in August, but the warm water did not penetrate to so great a depth. At 50 fathoms, 65° was found in August, but only 59° in April. Sir Wyville Thomson remarks : - '* Where the rate of the current is highest, we have as usual a rapid fall in the temperature below the surface. This is caused by the cooler water rising to supply the place of the hot surface water, which is being rapidly drifted and evaporated away."

(282.) At the distance of about 177 miles South of Cape Palmas (long. 73° W.) the outer border of the Guinea Current sets to the East; and it continues in the same direction to a similar distance South of Cape Three Points (long. 2° W.); we thence, at 2° North of the Line, find it take a more Northerly course, toward the Bight of Benin and the Bight of Biafra; in the latter it mixes with the waters of the South African Current, which, coming from the South, sets thence to the North and N.W., and both, uniting, form a head in the bight. From this bight and Southward of the Equator the Currents thus blended set to the S.W., W.N.W., and N.W. in one expanding and united stream, which greatly facilitates the passage of ships from Fernando Po to Sierra Leone.

The prevalence of the Harmattan wind, described on pages 164 - 168, must interrupt the course of this Current ; but its existence, at other times, nearly as described, has long been confirmed, and is incontestable.

(283.) Near Cape Mount the Current sets in towards the shore as above stated. The ship Charles, a French whaler, in 1833, was wrecked on the coast of Liberia, about 90 miles to the S.E. of Cape Mesurado, probably on the reefs near the River Sestros. This vessel had left the port of Havre for the fishery near Tristan da Cunha, in the Southern Ocean, but the captain, intending to run along the coast beyond Cape Palmas, in the hope of falling in with whales, unfortunately lost his reckoning, by being deprived, for forty-eight hours, of all means of taking observations; and was moving at the estimated rate of 7 miles an hour, when he found him- self close on shore in the midst of breakers, which in the course of the night forced him on the reef, and dashed the ship to pieces. The captain and crew got safe to land, but were soon stripped by the blacks. In this condition they made their way along the shore to the N.W., until they reached Cape Mesurado, where they were received with all kindness by the colonial agent of Liberia. The catastrophe is evidently attributable to this Easterly Current.

Captain C. T. Rudge, ship Jane Black, December, 1856, says : - " It is my opinion that the current along the coast from the Bissagos Shoals to Cape Palmas is variable ; and in the parallel of Cape Mount, coming from the Westward with S.W. winds, I have always found northing in the set, let the current be Easterly or Westerly. Ten miles off the land the current runs parallel to the land either way, strongest off the capes. I have com- manded ships on the West coast of Africa 12 years, and have found the currents very variable at all times."

On the Western side of Cape Palmas it sets along shore with such force to the S.E., that ships which do not steer a point nearer than the true course will be carried from the land. About Cape Three Points, likewise, the stream runs strongly to the Eastward, and frequently sets directly in upon the reefs about that cape. Hastward of this cape the Current has carried many experienced mariners, bound to Cape Coast or Annamaboe, to leeward of those ports, and occasioned much trouble, with delay, in beating up again. About Zerra Formosa, in July and August, the Current has also been found to set strongly to the Hastward.*

* In the Derrotero de las Antillas the following remarks are said to have been found

(284.) Enseigne C. Martin states that from the experiences of French cruisers on the West coast of Africa, it is found that between the Canaries and Cape Palmas the current is very weak and close to the coast, being rarely felt Westward of long. 16°. From Cape Palmas to Cape Formosa it follows the trend of the coast, and appears to divide against the latter cape, a weak portion continuing its course between the Niger and Fer- nando Po, the main body appearing to trend off to the South and 8.W. In the channel separating Fernando Po, Princes, and St. Thomas Islands from the coast, the current was generally found running N.W., perhaps due to the outflow of the River Congo. Here this seems to meet the 8.W. branch of the Guinea Current, and the two combining bear off to the Westward as the Equatorial Current.*

(285.) Mr. J. Y. Buchanan, F.R.S., gave a paper at the British Associa- tion, 1892, '' On the Temperature, Density, and Motion of the Waters of the Gulf of Guinea," from observations made in the telegraph steamer Buccaneer, in January, February, July, August, and September, 1886. He states that the surface-water of high temperature all over the Gulf of Guinea forms a layer of generally not over 30 fathoms in thickness. A moderate breeze off shore easily blows it away, and its place is taken by the denser and colder water immediately below it. Generally, the current along the Guinea coast was found to set strongly to the Eastward, as the well-known Guinea Current, and this was confirmed by the current bottles thrown overboard and afterwards found. In the Bight, near the Island of St. Thomé, the current set in a North-Westerly direction and was strong enough to set the ship back, while heaving in the sounding wire, by about as much as she steamed forward between soundings.

Between Ascension and Conakry, some interesting current observations were made in the neighbourhood of the Equator. Here a strong current to the Eastward was found at 50 fathoms, as much as 1°3 knot per hour, the surface-water setting to the Westward at about 0°5 knot per hour; so that the net Easterly current below was at least 0°8 knot per hour.

The change in the character of the Current at different times is shown by the fact that from the Equator towards Sierra Leone, in March, the Buccaneer experienced no Easterly curreut, and a bottle thrown overboard was washed ashore on the Kroo Coast, whereas, if the same current had prevailed in both March and January, the bottle would have been carried round Cape Palmas and into the Gulf of Guinea.

(286.) Thus far, we give a general description of this remarkable Current. What follows is from the Meteorological Office Monthly Analysis, 1872, with which is incorporated further information gained from a study of Captain Toynbee's work on the Meteorology of the Area included between

among the papers of the deceased Admiral Don Josef Varela. '' At Prince's Island, and in its vicinity, the waters generally run to the North, which circumstance ought to be kept in mind in making the island, and steering for the anchorage. There are also currents to the South, but they are not so strong, nor of so long duration. The pilots of the place say that the currents depend on the phases of the moon, but we found that they were irregular."" From this we may infer that there is some irregularity in the outset or revolving current ; for which, consequently, every precaution should be taken.

logical Office, in 1876. (See the Diagrams illustrating the Best Monthly Routes Across the Equator).

The observations made on the Western portion of the Guinea Current are neither as complete nor as numerous as might be wished, nevertheless they lead to the conclusion that from the 20th meridian Westward this Current undergoes periodical changes. We shall make this evident from a tabular statement of the information yielded by the charts illustrating the above-mentioned works.

On 20th meridian flows

Chart. Commences in - between latitudes - Gonoralieess core scsctesecerees ieee | 50° W. 8° N. 8° and 10° N, URINE TAY oeaqcdundeosocosonesucnecss 25 6 2 53) eo A\FaystI" sprsssaeobeinsesosenapasseaSoss 25 6 PA vee 1, SUNG Sie eccsmecccesets-ciescensnneons 30 6 Bikes September ..........ssccccseserees | 37? 8 Oh ale INOVOMI Pero scsccccesssacenccesees 30 6 3 OD e16 December jicscdesosacshocceessneoss 23 5 73.34 40

Tt thus appears that the Guinea Current has its maximum extent in August, reaching to 45° W., and occupying 11° on the meridian of 20° W.; and having its minimum extent in December, attaining long. 23° W., and having a width of only 7° on the meridian of 20° W. From December to August it is extending its longitude Westward, and widening Northward ; and from August to February it is losing its extension Westward, and its Northern limit is retreating Southward again.

(287.) In January the Guinea Current appears to originate about long. it is joined by the North African Current, which checks its tendency to the Northward, and the united waters flow Eastward along the coast of Guinea, being traceable nearly to Fernando Po. From its origin to Cape Palmas its rate is from 10 to 15 miles per day, but off this cape it acquires a greater velocity, ranging from 13 to 35 miles per day, which it maintains until it reaches the meridian of 5° E. The Southern limit of this Current is probably about lat. 2° N., but observations are here wanting.

In February it commences in long. 25° W., lat. 10° N., but is seldom felt so far West. From the 20th meridian it is well defined up to Fernando Po, trending Southward to St. Thomas, its Southern limit being about

* During February and December, frequent Westerly Currents have also been re ported here.

24 hours, and seems to be occasionally reversed ; from 7° to 0° W., its rate has been observed to be as much as 44 miles, though this can hardly be usual; farther Eastward the rate varies from 13 to 24 miles. An eddy current is indicated in the Bight of Benin.

In March the Guinea Current can be traced from lat. 13° N., long. 28° W. At first it appears as a weak current having a rate of 5 to 10 miles in the 24 hours; but near the African coast, and in about the region of 2° N. and 18° W.., its velocity increases to 20, 30, and 40 miles, the strongest current being marked on its Southern limit.

In April it commences in about 6° N., 25° W., and rapidly widens till it extends from 8° N. to 2° N. on the 20th meridian, with a rate of 12 to 23 miles. It maintains about the same rate to long. 8° W. Between 5° and 0° W. its rate is from 26 to 36 miles; farther Eastward it loses strength, and either dies out in the vicinity of Fernando Po, or is deflected Southward, and drawn in with the Equatorial Current. The Current has been observed to run strongly to the Southward, in lat. 12° N., 28° W.

In May it seems to be felt at times as far West as 35° W., about lat. 2° to 5°N. In 30° W. it is farther North, and on the 20th meridian it lies between lat. 3° and 10° N. Along this route its rate is from 13 to 33 miles. As it nears the African coast, it is felt at times as a Northerly Current, probably influenced by the wind. Here, too, its rate is from 12 to 13 miles. In the Gulf of Guinea it is Easterly, the rates varying from 16 to 45 miles.

In June the Guinea Current probably commences about lat. 6° N., long. 30° W. hence it spreads Northward and Southward, so that when it crosses the 20th meridian its width is from lat. 3° to 8° N. Its rate thus far is from 15 to 20 miles. Between 20° and 25° W. the North African Current is running strongly to the Southward between lat. 8° and 18° N. The Southern portion of the Guinea Current finds its way, but with con- siderable northing, into the Gulf of Guinea. Here its rate is strong, from 16 to 36 miles, and it appears to be confined within narrow limits of lati- tude. A counter-current has been observed in the Bight of Biafra. Captain Toynbee remarks : - '' The Easterly Current on the coast of Africa has become stronger since May. Perhaps this may be accounted for by the fact that the N.E. Trade extends much farther North than in the winter, drawing more water off Africa, whilst there are fewer Westerly gales in the North to heap water against Africa, hence the deficiency must be made up by an increased Hasterly current near to the Equator. It will be seen that it does increase in amount, and becomes more North-Easterly near the coast of Africa as the summer advances."

In July it is indicated about 6° N. and 42° W., if the observations here are trustworthy. Observations are wanting to the Eastward till it crosses the 35th meridian, between lat. 7° and 11° N. In long. 20° W. it extends from 4° to 12° N., its rate being from 15 to 20 miles a day. A portion of 'ts waters is turned to the N.W. by the coast about lat. 10°N., and passes io the Northward past Cape Verde, but the main current passes into the Gulf of Guinea, attaining a rate of 28 miles. Between the meridians of 10° W. and 0° there are no observations of this Current, but it is shown Eastward, between the coast and lat. 2° N., where its rate is from 32 to il

miles. Although the Western limit of this Current is not well defined, the data show that its rate and extent are remarkable.

In August the Guinea Current is indicated between lat. 8° and 10° N., in long. 45° W., and from 40° to 30° W. there are but few observations. It appears, however, to be running at a velocity of from 15 to 20 miles day in this region to the Southward and Northward of Hast. At 30° W. At this part its rate is between 10 and 25 miles per day. Farther Hast- ward it is stronger, and off Sierra Leone has a velocity of 50 miles, with direction Northward of East. Abreast Cape Verde it neutralizes the North African Current.

In September it can be traced to 37° W. longitude. In long. 30° W. it rate is from 8 to 32 miles. It maintains about the same rate in the Gulf of Guinea, where its Southern limit is about lat. 1° or 2°. N. Its velocity is increased to 30 and 40 miles in the 24 hours in rounding the Coast of Liberia. It appears to neutralize the North African Current in about lat. 12° N., Southward of Cape Verde.

In October it has been noticed in 50° W., between 5° and 10° N. Thenee to 30° W. there are only a few observations. At 30° W. it extends from variable, though the general tendency towards Africa is evident. Between 15° and 20° W., and 4° and 8° N., it appears as a strong Current, with a velocity of 30 to 40 miles in the 24 hours. In the Gulf of Guinea its rate is greater than in 20° W., but nowhere exceeds 23 miles. The isotherm of 80°, in lat. 3° N., seems to mark the border of this Current.

In November it cannot be traced farther than 32° W. At 30° W. it to be now losing strength and regularity. From 20° to 10° W. the obser- vations are deficient in number. Off the Coast of Africa it runs more to the Southward of East than in previous months, indicating the effect of the Westerly winds North of the N.H. Trade, driving water against Africa, which runs to the Southward. In the Gulf of Guinea it is also feeble and unsettled as to direction.

In December the Guinea Current is indicated in 23° W., latitude 4° to 6° N. The set is irregular, and the rate feeble, from 11 to 14 miles. It has contracted in breadth since November. At longitude 18° W., its breadth is probably from 3° to 10° N. latitude. Thence to longitude 10° W. observations are wanted. The Current has been observed far to the Westward in this month, in one or two instances between lat. 6° and Gulf of Guinea it flows between the coast and lat. 24° N., at a rate vary- ing from 20 to 36 miles,

(288.) The central portion of the North Atlantic Ocean, which is com- prised between the Trade Wind and Anti-Trade Wind systems (42), page 124, also bounded on the South by the Westerly Drifts of the Trade Winds, and to the North by the Easterly Current, presently described, appears to be in a different physical condition to the other portions of the Atlantic Ocean, and indeed from any other portion of the globe.

Its apparently chief characteristic is well expressed by the name now usually applied to it - the Sargasso, or Weedy Sea. The well-known gu/f- weed, which is found more or less over its whole area, seems to be quite peculiar to it. There may be a somewhat analogous physical condition in the North Pacific Ocean, but this is not so easily defined. This gulf-weed is constantly found, in greater or less quantity, scattered over its whole area, and when it is found in places not its usual habitat, it may be safely inferred that it has drifted out of this extensive area by the action of the

(289.) It is very difficult to define the limits within which this gulf-weed is found. The fluctuations of the seasons greatly affect them, as they do the limits of the Trade Winds and intervening Calms, the more particularly as it is to the varying Currents caused by these winds that the weed is retained in its locality. Consequently, we may look for its North and South boundaries more to the Southward during the Northern winter months, and the reverse during the summer. The Tropic, or about the parallel of 23° N., may be its Southern edge in the longitude of the Azores, from whence this limit extends to the Virgin Islands and the Bahamas. Its Northern edge runs from the Azores to the outer edge of the Gulf Stream off Cape Hatteras. This will give a breadth of 1,000 miles in its Eastern part, and a length of 3,000 miles from East to West. As before stated, its limits may change greatly at different times, but it may always be looked for within this area, that is between the Southern edge of the Gulf Stream and the Northern limit of the Equatorial Current.

According to the investigations of Dr. O. Kriimmel,* the area of maximum weediness (where the weed covers from 10 to 25 per cent. of the surface) forms an ellipse between lat. 25° and 35° N., and long. 40° to 73° W. The weed has been found as far North as lat. 52°, in long. 45° W., and as far South as 15° N., but it is only found Northward of lat. 45° N. in late summer and autumn.

(290.) There has been much speculation as to the causes and conditions which have made and retained this peculiar area in its integrity.

* A good account of this weedy sea, which is called by the French '' Mer de Varec'h," by Captain Leps, of the French Navy, is given in the " Annales Hydrographiques,' 1857, page 565, &c.; another more recent account, illustrated by a map, is given by Dr. O. Kriimmel, in Petermann's " Mitteilungen," 1891, pp. 129 - 141. As the con- clusions there arrived at entirely accord with the particulars given in this volume, it has not been thought necessary to quote from them to any large extent,

Major Rennell says: - It has been observed that the waters of the Atlantic have a greater tendency toward the middle of the Ocean than otherwise, and this seems to indicate a reduced level, forming a kind of hollow space or depressed surface. It is certain that the setting of the Currents is such as might be expected to take place if such a hollow existed; for the Currents do really set into the Sargasso Sea from the North and from the South; whilst in the middle part, although within the region of the Trade Wind, the Currents are not regular, but indicate a kind of

By others it is considered as an immense eddy or whirlpool, formed by the inclination of the water to the Westward, caused by the influence of the Trade Winds and the Gulf Stream.

Others, again, argue that it is a raised surface, maintained in a quiescent condition by the surrounding currents, and retaining all floating matter that is poured into it by the surrounding influences.

It is also considered as the grand receptacle of the Gulf Stream, which, recurving at the Azores, here turns into this space ail that it has trans- ported through its long course.

All these theories have some facts to bear them up in some degree, but others can be adduced to show their futility.

(291.) Itis here urged that a simple explanation can be given of this curious region, in the analogous condition of the atmosphere, so powerful an agent in the production or alteration of Ocean Drifts and Currents.

By referring to Maury's Trade Wind Charts, cited on page 128 (48), it will be seen that there is an uncertainty about meeting with the Northern edge of the N.E. Trade Winds through an extent of at least 10° of latitude; add to this the vibration of this zone of Trade Winds consequent on the motion of the sun in the Ecliptic, which amounts to from 5° to 8° in latitude, as exemplified in the diagram of the limits of the Trade Winds at page 125, and we have a range of 15° to 18° of latitude over which, during some portion of the year, and over a large section of it throughout the year, there is nothing but light airs and variable winds, being, in fact, the

Under this zone, therefore, the sea is subject to no continued or regular drift, and, consequently, whatever is thrown on to its surface will remain for a long time, and the Sargasso, or gulf-weed, being one of the few marine plants which lives when broken from its rocky bed, may exist here for a very long period, and thus accumulate by the fresh additions constantly brought by the outer or Eastern edge of the Gulf Stream, as well as that drifted around the Northern part of the Atlantic, and passing with the S.E. current by the Azores (262) into this quiescent zone. That the Gulf Stream is the primary feeder to this weedy sea will be shown presently.

(292.) There is another condition, also, which favours the maintenance and growth of this peculiar plant. The temperature of this water is very equable, less warm than that under the more vertical sun, and not varying more than 6° or 7° Fahr. throughout the year in the Eastern part, or 8° or 9° in the Western part. This temperature is, as said, lower than that of

* Rennell's "Investigation," page 72.

the Southern part of the great Equatorial streams to the South of it, but it is higher than that of the Current which sets S.E. and South between the Azores and Spain, and lower than that of the surface of the Gulf of Mexico and the early course of the Gulf Stream. It may, therefore, be considered that it approximates to the water-climate of the bottom near the shores of the Gulf of Mexico, that of the sea around the Bahamas, &c., where it is known that this weed grows naturally.

(293.) The Sargasso or Gulf-weed, which is the peculiar characteristic of this area, is one of the few plants, aquatic or terrestrial, which will live and flourish when separated from its native stem. Its appearance is too well known to require any detail. The sea was called Sargagao by the early Portuguese navigators, from the weed bearing berries like grapes, '"'garga."' This term has thus been corrupted into Sargasso, and been applied. to the plant itself instead of the place it grows on. There are more than one species of it known to botanists, as sargasswm vulgare, &c., distinguished from each other by the form of the leaves and the fructifica- tion. These different species are more or less abundant in different localities. It is frequently called fucus natans - floating sea-weed; and is known to sailors as gulf-weed, that famous stream being always more or less marked with it.

(294.) The old story of Columbus, wno had much difficulty with his men, when they declared that even the sea changed its nature into terrestrial to prevent his proceeding on his discovery voyage to America, has been oft repeated. In his account he stated that ''sometimes the weed comes in such compact masses as to cause the sea to look like a coagulated mass."

The sea is commonly studded over, like an inundated meadow, with the bushes, which arein some places very abundant, and in others more dis- persed. If we imagine the surface of a wide extended moor, covered with water, the furze and heath bushes would appear something like the clusters of fucus scattered over the thickest part of this sea.

The fructification of all sea-weeds is peculiar, but they require a fixed basis to vegetate. Although apparently flourishing in vast areas in the Sargasso Sea, they can only be looked on as cut flowers rather than as complete plants, although their constitution enables them to live a long period without being fixed to their parent rock like most other alge. They are found in every state of decay, and when old they become covered with minute and beautiful parasitic growths, which deserve much attention by those who have the leisure and taste to examine them, especially with the microscope, which in this region reveals a vast and little known world. Besides this, too, the tufts afford protection and shelter to a vast quantity and variety of minute fishes, crabs, and other crustacea and animalcule, which will afford an inexhaustible fund of interest to the observer. Naturally enough, there is a limit to its separate existence, and when subjected to any change of temperature, or difference of locality unsuitable, by a continuous wind or current, large areas become decayed, die, and sink to the bottom, to be renewed by the continual fresh importations from the Gulf of Mexico.

It is sometimes drifted on to the shores of the British Isles and Western

Kurope, and appears among the other sea-weeds in the various works on algology, but it is accepted as a shipwrecked stranger, not as a native of our shores.

(295.) The Gulf of Mexico abounds with the native growths of the Sar- gasso weed. It is found attached to the rocks, at the bottom, in most parts of it. The soundings on the Campeche Bank, Chiriqui, the Andros Islands, on the Bahama Banks, New Providence, &c., all furnish the supply of growing plants. The spores (or seeds) of these become attached to these rocks in the manner usual with all algz, and the young plant grows, not from a root, because the attachment to the rock is not of that nature, till it attains some size, when offering greater resistance to the progress of the continual current than the stalk is able to bear, it becomes detached, rises to the surface, and then is borne onward by the stream till it emerges through the Gulf of Florida by the Gulf Stream. As will be shown here- after, this stream has a tendency to throw all floating bodies off to the right-hand of its course; it follows, that this weed is gradually cast off into this central area, aided probably by the Westerly prevalence of the winds which at times occur in this part.

One opinion may be safely controverted, that which assigns the depths of the Atlantic over which it is found as its native place. The great depth and consequent cold disproving the possibility of a plant living in such extremes of temperature.

In the Paper mentioned in the note on page 335, Dr. Kriimmel ecaleu- lates that after leaving Florida Strait or its vicinity, it would take about six months for this weed to reach a position West of the Azores. It then moves away very slowly, and gradually decays and sinks.

(296.) H.M.S. Challenger, in crossing the Sargasso Sea (June 14th to July 1st, 1873), found the Current variable, both in strength and direction ; westward of 38° W. was between 2,000 and 3,000 fathoms, with a bottom of oaze, and with no signs of weed, disproving entirely the idea of some naturalists that the weed grows in this locality. Hastward of 38° W., the depth varied from 1,675 to 1,000 fathoms. The temperatures of the sea surface were greater in the Western part of the district, 734°, than in the Eastern, where it was generally found to be about 71°; at 100 fathoms the temperature was about 66°; at 500 fathoms about 483°; and at 1,000 fathoms about 374° Fahrenheit.

"The floating islands of the gulf-weed, with which we had become very familiar, as we had now nearly made the circuit of the 'Sargasso Sea,' are usually from a couple of feet to two or three yards in diameter, sometimes much larger; we have seen, on one or two occasions, fields several acres in extent, and such expanses are probably more frequent nearer the centre of its area of distribution. The general effect of a number of such fields and patches of weed, in abrupt and yet harmonious contrast with the lanes of intense indigo which separate them, is very pleasing. These floating islands have inhabitants peculiar to them, and I know of no more perfect

example of protective resemblance than that which is -hown in tha gulf- weed fauna." - Sir Wyville Thomson, '' Voyage of the Challenger," vol. ii.,

(297.) Captain Andrew Livingston, on his way from New Orleans to the Strait of Florida, saw large quantities of it; and every one who has navi- gated the Gulf Stream has remarked the weed in it, or along its borders. Sir Philip Broke and the Baron Alexander von Humboldt say that the stream contains a great deal. Sir Philip says, '' We were always surrounded with gulf-weed."' Major Rennell adds, '' He spoke of that part of the Gulf Stream out in the Atlantic; the others might speak of other parts."

In the "Sailing Directory for the Windward and Gulf Passages, the Bahama Islands, &c.," by A. G. Findlay, is a description of Andros Island, and it is there shown, that in the great sponging district, upon the Bahama Bank, West of Andros, vast quantities of the gulf-weed are produced ; and this is one of the beds from which the ocean has been supplied.

On this subject, we have the following remarks by Captain Livingston, whose name has so frequently occurred in the preceding pages : -

'« Many persons suppose that the gulf-weed (fucus natans) grows upon the rocks about the Bermudas; others, that it originates among the Florida Reefs ; and a third party, that it grows upon the water without ever adhering to anything fixed.

'* All these positions seem to me equally wide of truth. Neither on the Bermuda Rocks, nor among the Florida Reefs, has a single branch of gulf- weed ever been found growing upon the rocks; and, among all the gulf- weed met on the ocean, no person has ever found a single tuft with roots, or that, on mature examination, could be supposed, by any person of sound judgment, to have grown on the surface of the water. On the contrary, every stalk of the weed seems to have been broken off short from some- thing to which it firmly grew, and all the ends of these stalks are uniformly decayed, or dried up, from the end to a short distance.

'Tt has been stated, as a well-known fact, that the fucus natams grows on the rocks along the Gulf of Paria, and on the coasts of Caraccas, &c. If this be the case, it is rather strange that it should not rather grow on other rocks and coasts of the West Indies. It has also been stated, that in the whole sea of floating bushes, Mar do Sargasso, not a withered plant is ever discovered. This is not true, as I have seen abundance of fucus natans in a state of great decay. I note the following from my journal of the Brilliant, from Gibraltar towards Havanna: February 8th, 1819, 'the weed much decayed ;' 9th, a.m., 'weed passed through, much decayed ;' 10th, p.m., ' passed through much decayed weed; I remark, that the farther we run to the Westward, the more decayed is the gulf-weed;' 13th, 'the gulf-weed begins to look fresher.'*

'« These particulars have been given in order to show that I have not spoken at random; on the contrary, actually made my remarks on the spot.

* On the 8th of February, the Brilliant was in 24° 17' N. and 65° 1' W. On the 9th, 25° 34' N. and 71° 5' W. On the 9th, the ship passed the meridian of Porto Rico, and was hence proceeding toward Providence Channel, Bahama. The decayed weed, wa have no doubt, had drifted from the central area of the ocean. - Fin.

Some of the weed was quite brown, and in small fragments, evidently separated into such by its state of decay. It is true that the weed soon decays when it is taken out of the water, as I have often tried the experi- ment. The weed is never of a verdant green colour, but seems as if blanched from having been, in some degree, hid from light; I suppose from vegetating under water."

(298.) Mr. Turner, and many other botanists, thought that the greater part of the fuci (weeds) which we gather on the surface of the ocean, and which, from the 28rd to the 35th degree of latitude, appear to the mariner like a vast inundated meadow, grow primitively at the bottom of the ocean, and float only in their ripened state, when they are torn off by the motion of the waves.

«The causes that uproot these weeds, at depths where it is generally thought the sea is but slightly agitated, are not sufficiently known. It has been said, that if the fucus adheres to the rocks with the greatest firmness before the display of its fructification, it separates with great facility after this period, or during the season which suspends its vegetation, like that of the terrestrial plants. The fish and the mollusce that gnaw the stems of the sea-weeds no doubt contribute also to detach them from their roots.

'"«On proceeding hence, toward the West Indies, from the 22nd degree of latitude, we found the surface of the sea covered with flying-fish, which threw themselves up into the air 12, 15, or 18 feet high, and fell down on the deck. I do not hesitate to speak of an object, of which voyagers discourse as frequently as of dolphins, sharks, sea-sickness, and the phos- phorescence of the ocean. None of these objects can fail of affording interesting observations to those who make them their study."'

(299.) Captain Bourke, in the brig Archibald, December, 1815, found large quantities of the weed near the parallel of 20°, to the Northward of the Island Porto Rico, and of the Eastern part of Hayti; but on the passage through the Bahama Channel, Eastward of the meridian of 70°, and on the North sides of Hayti and Cuba, none of the weed was seen. This may be accounted for on the supposition that it was drifted by the current from the great bed of weed to the N.E., as before explained.

Lieutenant John Evans, R.N., states: - ''In November, 1810, H.M.S. Belvedere, in the centre of the Atlantic, lat. 33° 20', long. 41° 37', passed through prodigious quantities of fucus natans, in line North and South, as far as the eye could see; and, notwithstanding that there prevailed a very heavy swell from the North, their position was not altered. The quantity of this weed met with between the 30th and 36th degrees of latitude is really astonishing ; at times you may sail for leagues through it, covering, as a mantle, the surface of the sea. I have often seen it in lines about 300 or 400 fathoms in length (sometimes only a few yards), and frequently in large and small patches of irregular shape, but generally in a circular form. The deep-sea line should be put over the side frequently in this particular part of the Atlantic."

On the 17th of April, 1828, at noon, in the Mexican Sea, a vessel, under the command of Lieutenant John Evans, was in lat, 26° 52', long. 89° 17'. On this day fucus natans, or gulf-weed, was seen, in parallel lines, 8.8.E. and N.N.W. It was in flower, and completely covered with young bar-

nacles. '' From lat. 25° to 28° in this sea we met with fucus in parallel lines, S.S.E. and N.N.W.; it flowers like fern and other cryptogamia. In calms, the fuci float near the surface, some of the leaves appearing above water; the patches seen in the Florida Stream, and the bunches examined, were old, brown, and covered with young barnacles."

In the year 1825, the brig Hrin, from the Pacific Ocean to Liverpool, when to the Westward of the Azores, passed compact parallels of fucus natans, in lat. 39° 59', long. 33° 46'. The weed was less broken than any they had before seen; the medules large and of a deep yellow-brown colour, and the lines extending, as far as the eye could reach, in a direction about S. by E., being nearly at right angles with the vessel's line, which was K. by N. The wind was 8.E. by S., strong gales and a heavy sea.

(300.) The fucus natans is found in localities to the Hastward of the Sargasso Sea. For the following communication we are indebted to the late Captain Thomas Midgley, and it is a great acquisition to our know- ledge of the wide range that this plant has : -

"On my outward passage to Africa, in a perfect calm, at daylight on the I found the ship amongst a number of small bunches of weed, and many cuttle-fish shells.

'On carefully examining some of the bunches of weed, I was surprised to find it the true fucus natans, or Sargasso or gulf-weed, being in every respect precisely the same as that found in the N.E. Trades, but apparently much fresher, having exactly the same kind of oblong, narrow, serrated leaf, same stem, same nodules, and just the same pale yellow colour. The pods were also surrounded with a very fine kind of network (flustra), and there were a very few minute barnacles attached to the stem, which scarcely showed any marks of decay; indeed, the two bunches brought on board (which were each about 4 inches in diameter) appeared to hava been but very recently separated from the parent stem, and they each contained a small but very lively crab.

'"« The lively fresh appearance of the weed, and the two crabs, induced ne to try for soundings, and, as the weather was perfectly calm and the water smooth, I was enabled to get a perpendicular cast of 112 fathoms, with a well-armed heavy lead, but found no bottom.

'The weed was in detached and small bunches, and could only have tended over a comparative limited space; for when a breeze of wind sprang up, and the vessel had sailed 20 miles to the Eastward, there was not a single sprig or bunch to be seen.

'This weed appears to be unknown upon the Kroo coast, for I had two intelligent natives of Sangwin and Grand Sestros on board at the time I picked the weed up, and they severally declared they had never seen it upon any part of the coast.

'The vessel had been perfectly becalmed for fourteen hours previous and two hours subsequent to the time of picking up the weed, so that she gradually drifted amongst it by a current, which I found, by good observa- tions and carefully-kept reckoning, to set E. by S. by compass, very nearly three-quarters of a mile per hour. Temperature of water, when weed was picked up at daylight, 79°, and at noon, 81° F

(It had evidently been drifted out of the area by the Guinea Current, described on pages 325 - 334. Its not being known farther East is probably owing to the difference in the temperature of the sea, which kills the weed before it can arrive there).

(301.) Mr. Luccock, in his '' Notes on Brasil," likewise described the Green or Weedy Sea. He states that it extends from 11° to 35° of North latitude, and from 30° of longitude to an indefinite distance Westward. "Here," he says, ''the ocean is covered by nodules of sea-weed, from 3 to 18 inches in diameter, somewhat resembling in form a cauliflower when stripped of its leaves. They float lightly on the water, in parallel lines, at a very few yards from each other, and have a yellow-brown colour, like the long stringy fibre which is sometimes seen floating in the English Channel, and which I suppose to be the natural colour of all marine plants, growing deeply beneath the surface of the water. These nodules, or spherules, are composed of a vast number of small branches, about half an inch long, which shoot from each other at an angle of about 40°; hence they multiply continually towards the superficies of the sphere; and each extreme point produces a round seed-vessel. This is little more than one-tenth part of an inch in diameter, is hollow, and contains a small reddish-brown seed, scarcely occupying one-fifth part of the husk. The leaf of the plant springs from the joints of the branches, is oblong, indented at the edges, about 14 inch long, and a quarter of an inch broad.

'"' When the nodule is dexterously taken up, all the branches may be traced to one principal stalk; and this invariably shows a fracture, the part by which it has been joined to some larger stem. This fracture is frequently quite fresh, and, in large and vigorous plants, shows distinctly a woody part and a cortex. On the edges of the latter, the first symptoms of decay appear. They become brown, and separate themselves from the wood. This, also, then assumes a darker colour, and exhibits the regular process of disorganization, just in the same manner as does a slip from a currant or gooseberry bush. In process of time, the whole of the plant assumes a darker hue; and, as it decays, floats considerably lower than it did. When kept out of the water for a few hours, it becomes harsh and brown, and acquires the peculiar smell of marine vegetables in a state of

"A great number of very minute barnacles are found upon the leaves and stalks. The seed-pod is usually enveloped in a sort of honeycomb work, which may be taken from it, and, when examined by a lens, resem- "bles in appearance the network of a fly's eye. (This is.called flustra). Among other inhabitants of the plant is frequently a number of small crabs, perfectly formed, and evidently young, yet vigorous and active ; and when a nodule, taken fresh from the water at night, is hung up in a small cabin, it emits phosphorescent light enough to render objects visible.

"The singular arrangement of the plants, in parallel lines, is evidently owing to the wind, whose direction they always observe. Each nodule places itself under the lee of its more windward neighbour, and thus ob- serves the law of floating bodies when exposed to a current of air. Should | the wind suddenly change, as it sometimes does, a point or two, in this part of the Atlantic, and blow strong, these lines become broken, and form

what are commonly called fields of weed. These, however, are generally small, and seldom, I suspect, remain long so disarranged."

Mr. Luccock was of opinion that the weed grew on the bottom in the area where it is found floating, but more recent explorations have disproved this; as before stated.

(302.) The name which is usually given to the great Drifts of the Trade Winds, having as wide a range of latitude as 50° or 60°, is scarcely expres- sive. The Hguatorial Current, strictly speaking, is the counter-current we have just described. However, the Drift which is intended passes to the S.W. and West of the Azores and Canaries, and from the Coast of Africa to the Gulf of Mexico, Northward of the Easterly Counter-Current in the North Atlantic; while the great Drift of the S.E. Trade Wind, crossing the Equator Southward of the Counter-Current, and running strongly to the N.N.W., along the coast of Guayana, joins its strength to the Northern portion, and thus, together, they pass between the islands and through the Caribbean Sea.

The Drift of the N.E. Trade is not so poueee as that of the 8.E. Trade, as the interference of the land causes such a great change in the regularity of the winds which certainly must be taken as the greatest cause in the production of these currents. In general, it is a very feeble current, and the mean rate has been over-estimated in former times by many observers. In its Northern limits in the open ocean its annual average, from a careful calculation, amounts from 8:2 miles to 11:6 miles per day; in its Southern and stronger portion it is from 16 to 22-4 miles per day. Westward of the Cape Verde Islands, its mean direction is nearly due West, which is remarkable, considering the northing of the Trade Wind. It would seem scarcely necessary to enlarge much upon the rate and extent of this well- known current; but, as it may be interesting to compare individual ex- perience with that of preceding voyages, we give as heretofore a series of examples by which the ordinary rate and circumstances may be reckoned on,

ing the North Atlantic directly between the Canary Islands and Sombrero, the Northern extreme of the Caribbee Islands, found the Current to flow as indicated in the Current Chart, page 295 ; the velocities, however, were greater in places. In long. 19° W. the Current flowed to the 8. by W. at

from Barbuda), 10 miles N.W. ; and off Sombrero, 7 miles W.N.W.

The wind observed was about N.E., between the Canary Islands and 35° W.; thence Kast, with a little South in it as the Caribbee Islands were

The temperature of the sea surface was 64° F. at the Canaries, and increased, as the voyage proceeded, to 75° at Sombrero. A temperature of about 464° was found right across, at a depth of about 500 fathoms, and at 1,000 fathoms the temperature varied from 37° to 39°. Bottom

(304.) As it would be beyond the scope of this work to give a series of monthly charts, like those published by our Meteorological Office, although they are very interesting and most important, our remarks must be limited to those verbal extracts from that work, such as have been given previously.

The Westerly Drift.* - Under this name are included the Currents of the vast central expanse of the North Atlantic Ocean, bounded on the East by the North African Current, on the South by the Guinea Current, on the West by the chain of the West India Islands, and the Northerly and North-Easterly portion of the Gulf Stream, and on the North by the Easterly part of the Gulf Stream.

The Westerly set may be considered to commence at the 30th meridian. T'rom lat. 8° N., as its mean Southern limit, to the parallel of 20° N., the get is more constant and steadier than it is farther Northward. Indeed, as the latitude increases, the regularity of the set and the rate decrease. Here the latter averages from 12 to 24 miles a day, and this part of the Drift enters the Caribbean Sea with the Equatorial Current. Between the parallels of 20° and 25° N. the Drift averages from 8 to 12 miles, and can be traced to about long. 63° W. From 25° to 30° N. the set is irregular, and the rate from 4 to 1 miles, traceable also to long. 63° W. Between 30° and 40° N. the set is so irregular in direction and feeble in force as to lead to the conclusion that here the true Westerly Drift does not exist.

From lat. 36° N., long. 65° W., to the Bahamas, along the right edg

of the Gulf Stream, we find evidence of a counter-current setting to the S.W., and then to the South, at about 12 miles a day; and about lat 28° N., long. 78° W., turning to the S.E., in conformity with the contout of the Bahama Shoals. This South-Hasterly Current is probably periodical and seems at times to extend to long. 63° W., in lat. 34° N., its greatest rate not exceeding 15 miles a day. About long. 64° W., from lat. 20° to 27° N., there is a feeble Northerly set, but not supported by many obser-

(305.) In Janwary the Westerly Drift of the North Equatorial Current seems cvnfined to the Torrid zone, and to vary from 6 to 24 miles per day. 'There are indications of an Easterly Drift in lat. 23° N. Farther North the observations are deficient and conflicting, but indicate a Drift to the

'Southward of West.

* By this term it is to be understood that what we call the North Equatorial Currant

or Drift is meant.

In February the vast central area of the Atlantic Ocean appears to have variable currents, judging from the very few observations recorded for February. The Westerly Drift of the Tropics, if it exists at all, must be very feeble, not averaging more than 8 or 12 miles daily. Between lat 30° and 37° N., long. 42° to 65° W., the Drift seems to be Northerly, but the observations are not numerous. (See, however, the remarks relating to

In March it does not appear to extend beyond lat. 25° N. Between 27° and 55° W. observations fairly represent the general: Westerly set, while they give its rate at from 6 to 35 miles; it has its greatest rates in

In April the Westerly Drift may be said to extend to 30° N. The obser- vations differ greatly as to the rate, though they agree in indicating greater strength in the lower latitudes. In mid-ocean, between 30° and 40° N., the directions are variable, and the rates feeble.

*In May, North of the Equatorial Current to lat. 30° N., and from 25° W. to the West Indies, the general movement of the ocean seems to be to the Westward, at a rate of from 6 to 18 miles. In the Western portion of this region observations are, as usual, deficient.

In June it appears in mid-ocean and towards the Bahamas. It does not extend Northward of 30° N. The rates are various, 'and the observations are altogether scanty, as they are for July, August, September, and October.*

In November it exhibits a decided set to the Southward, between 25°

In December the Westerly Drift seems to maintain its usual gentle flow, but from lat. 20° to 40° N., long. 40° to 70° W., there are scarcely any data.

(306.) In the work (before mentioned in the note, page 136) by Captain Toynbee, avery full discussion of the direction and strength of the Currents verbal description of this work would give but a poor idea of its utility, and it has been thought best to give the information in the diagrams relating to the Best Monthly Routes Across the Equator, given hereafter, to which therefore the reader is referred.

(307.) It will be scarcely necessary to recapitulate the evidence upon which the mean rate was set down in the chart of the North Atlantic Ocean, before referred to (see (48) page 128). The General Chart of the Currents, at page 295, will, with the foregoing remarks, fully explain this part of the subject. As the Current is well established, we need not extract the numerous observations given by Captain Maury, as they almost all tend to the same conclusion. But the Drift of Bottles is so marked an evidence, that we give a number of instances which will be very instructive.

and South-Hasterly currents, of 7 to 21 miles a day, were experienced by three ships of the United States training squadron, where a decided Westerly drift is almost invariably reported. On the 11th, this Easterly set was lost, and the usual drift (W.N.W., 18 miles,) met with. The Trades were fresh, with no unusual meteorological conditions.

(308.) Bottles - The following have been selected from Captain Becher's list, explaining his Bottle Chart, in the '' Nautical Magazine,' of Novem-

| Where jeft. | Se Ship. | Signature. | - Where found. | 3 |S Ey a Latitude | Long. i ZA 2 Aint A lea Maid ea Means de a GO. ai ms MworBrothers....2.|ta.cccbaesomeccsss 1826] C. Verde Islands} Crooked Island | 3822800) 7

The mean rate of travelling of all these Bottles is 10°6 miles per day. But this: average requires several qualifications which will make it considerably higher. The distances are measured direct, but it is most probable that these messengers pursued a more or less devious course. Again, it will be seen that the Bottles thrown out on the Northern part of this Trade Wind drift have travelled much slower to their destination than those which started from near the Equator.

(309.) Besides the above, we add the following examples of Bottle drifts : -

Central Drift to the Virgin Isles. - A Bottle from the Emerald, Captain Nockells, Found on the North side of Anegada, January 8th, 1833. The winds for the last three days, previous to the 17th of December, were from North and N.W. to 8.W. - For eight days preceding these it blew a continued and heavy gale from S.W. and W.N.W.; the barque lying-to the whole time, and drifting from lat. 41° 28, 227 miles to the Northward.

Equatorial Current to Tobago - A Bottle from the-schooner Julia, William Davidson, master, in lat. 6° N., and loug. 40° W., November 6th, 1821. Found March 7th, 1822, near the shore of Little Rocky Bay, Tobago.

Central Drift and Equatorial Currents. - A Bottle from the ship Gambia, in the River Gambia, lat. 18}° N., in the latter part of 1831, was picked up on the Southern side of Virgin Gorda, lat. 18° 30.

Central Drift and Equatorial Currents - A Bottle from the Two Brothers, of

was found at Acklin or South Crooked Island, in Jat. 22° 12' N., long. 74° 18', on Deceinber 8th, 1827. Hence it appears to have drifted, in a W. by N. direction, from the vicinity of the Cape Verde Isles to the West Indies, under the influence of the drift from the N.E. and the Equatorial Current, probably, in the first instance, W.S.W. and thence W.N.W.

Madeira to the West Indies. - A Bottle from the ship Symmetry, of Scarborough, Captain Smith, on her way from Leith to Buenos Ayres, off Madeira, June 9th, 1825. Picked up at Salt Kay, Turks Islands, after a lapse of ten years, June 9th,

Cape Verde Islands to Brasil_ - The Hazard, of Greenock, August 4th, 1812, lost the N.E. Trade in lat. 11° N., long. 25° W.; and the wind, until the 12th, varied from West to S.W. ; from the 12th to the 17th it generally blew from South, never exceeding one point Easterly. Gained the 8.E. Trade on the 17th, in lat. 2' N., long. 27° 30' W.; the Trade kept Southward between Penedo de San Pedro, or St. Paul's Islets, and the coast of Brasil (at Rio Doce), and experienced a Westerly current amounting to nearly four degrees. Attested by Captain J. W. Monteath.

Between Madeira and Brasil. - In the Jane, Captain Livingston, April and May, 1824, found a surplus effect of currents, between Madeira and Brasilian Trinidad

A Bottle from the ship Hesperus, about lat. 37° N., long. 28° W., May 12th, 1878, was picked up at Mobile Bay, May 22nd, 1880, having covered a distance of about 5,500 miles, at the mean rate of 8 miles a day.

A Bottle from the ship Patriarch, in lat. 18° 29' N., long. 27° 8' W., December 23rd, 1884, was picked up in 1887 (? date), on the Eastern side of Caicos Bank, having drifted 2,523 miles to W. 4 N.

(310.) The foregoing is a sufficient elucidation of the features, velocity, and limits of the N.E. Trade Wind Drift of the Atlantic Ocean, but, as before mentioned, particularly in (53 to 60), pages 131 - 135, the division between the Northern and Southern systems of Wind, and consequently of Current, being to the Northward of the Equator, the South Equatorial Current ultimately combines with the North Equatorial Current, part of their united waters entering the Caribbean Sea, and forming the origin of the Gulf Stream, and the rest appears to trend off to the Northward out- side the islands, as explained hereafter, in the Section dealing with the Gulf Stream.

(311.) The South Equatorial Current, which passes over the Equator in its Northern portion, in its direction is, like that of the Northern Equato- rial Current, nearly due West. Setting upon the Northern coast of South America, it runs with great velocity close in-shore at times, sometimes reaching 100 miles per day, and not unusually 60 miles. It is scarcely necessary to dilate on this Current, as it appears to be regularly and con- stantly met with. Arrived to the Northward of Tobago, it combines with the North Equatorial Current, and the united streams thence proceed as described above. Its progress through the Caribbean Sea, &c., will be

dealt with in the next Section. For an idea of its strength and direction in the Equatorial region, between the longitudes of 10° and 40° W., the reader is referred to the diagrams illustrating the Best Monthly Routes Across the Equator.

(312.) It will be seen that, throughout the breadth of this Ocean, the set of the stream is not to S.W. or N.W., as might be expected from the direction of the Trade Winds, which may be taken as the prime mover of these mighty drifts, but Westward. This fact would seem to indicate that the rotation of the earth on its axis has more to do with its motion than has usually been attributed to it. But our present knowledge of the sub- ject is not sufficiently extensive or accurate to define what amount of action is due to that source, or how much to the wind, lunar influences, or temperature, all of which combine to produce the phenomena we are considering. Theoretical speculations, however, are not necessary in a practical work, although they may be interesting.

(318.) In the "Sailing Directory for the Caribbee or West India Islands," by A. G. Findlay, will be found '' Remarks on the Currents of the Atlantic and West Indies, made by Lieutenant A. H. Bisschop Greevelink, in the Echo, a brig of the Dutch Royal Navy, during four years of service, 1833 - 1837," and which describes the route of that vessel from England to Surinam, in August and September, 1833. 'On the evening of the 13th of the month, the Echo, having arrived in lat. 17° N., and long. 35° W., lost the Trade Wind, and the wind then shifted to the N.W., with a strong breeze; gloomy weather, and much rain, during the twenty-four hours. The following day the wind, diminishing, passed to the §.W. and §.S.E., and terminated in a calm; currents weak and variable to the §.W. and Eastward.

sprang up from the 8.E., and from that time till we reached the coast we had to struggle with a never-ceasing variety of wind and weather, continual rains with squalls, and scarce a day passing without lightning in one or other quarter of the horizon. On the 18th we passed by several ripplings or eddies, being then in lat. 12°, and long. 39°30' W. They usually stretched from East to West, and were often seen to cover the whole surface, every- where boiling and bubbling as in a cauldron. Current always weak, and during the last forty-eight hours to the West and W.N.W. at a rate of half a mile an hour.

«« After losing the Trade Wind we had to creep over more than 900 miles, as the wind had left us, in every appearance, for ever; the rains were copious and continual in this space, and lightning was seen very frequently. eddies; and on the 24th (lat. 8° 3', long. 45° 37'), the first indication of a change in the colour of the sea became visible; yet it was slight, and may be attributed to a branch of the Northerly current observed in the succeed- breeze, which brought us, though slowly, toward the coast. In the night of the 28th (lat. 5° 7', long. 49° 56'), we crossed the edge of meeting currents from the Ethiopic Ocean and Brasilian shore, and from the Marajion; after which, we entered the boundary of the tides. In the evening of

September 30th, came to anchor in 53 fathoms. In the night, observed longitude by chronometer, 54° 11' 45".

'« Although we had not seen land since we lost sight of the Lizard, by which to examine our timekeepers, I felt not the least doubt about their rate (the one a Knebel, and the other a Parkinson and Frodsham), by their reciprocal conformity, corroborated by my lunar observations (which, by-the-bye, I think are never to be neglected); and as I was desirous to obtain some observations about the Currents, so peculiarly remarkable in these seas, I took every opportunity which circumstances allowed to satisfy my curiosity.

"On the 22nd of September and subsequent days, the ripplings became less in number; and on the 24th, in the afternoon, about the 8th degree of latitude and 46th of longitude, we perceived the first change in the colour of the water from the common blue to a somewhat darker hue; and, as this was somewhat an uncommon case, I attributed it to a branch of Current observed the following day at noon, setting due North, at the rate of more than a mile an hour, straight across a South-Hasterly Current observed during the preceding days, mingling the muddy waters of the Maraiion and other rivers with those of the ocean. From the 24th to the 28th nothing particular occurred; we were always steering to the S.W. with light variable winds, and a continuance of rain sufficient to penetrate our very bones. Currents, weak and changeable, being lastly observed to run N. by W., 18 miles in twenty-four hours. This, at present, I call weak, being afterward accustomed to fall in with a velocity of twice and thrice that number of miles. At noon we altered our course to W.S.W., being

'Tn the night, however, having a lunar altitude, we were not a little surprised at finding the ship thrown 35 miles to the Northward of her sup- posed situation, although I may say to have been prepared for this occur- rence by Captain Edward Sabine's relation in the '' Memoir,"' whose track we were crossing just then, in the same month.

«« At break of day we saw the water totally altered in colour, and thickly mingled with mud, as if we were sailing in a flood of ochre; hove the lead, and found 45 fathoms, fine sand, white and black. At seven in the morn- ing, by chronometric observations, I found the Westerly offset 33' 38"; that the Current, in the last twenty-four hours, had been running with the rapidity of 67 miles to the N. 30° W. In the afternoon we perceived the land toward the 8.W. by S., being the Family Islands of Cayenne, and at the same time we entered the boundary of the tides.

'' This, indeed, seems to confirm the opinion of those seamen who attri- bute the principal strength of Currents hereabout to the waters of the Marafion, &c., predominating over those of the ocean; but this is to be admitted in a partial degree only; for, as operating on the general direc- tion of the Equatorial Current, I esteem it as of no influence at all."

(314.) The numerous voyages made by the Echo, in the West Indian Seas, with a particular detail of each, more especially in regard to the Currents, are given in the volume before mentioned ; and from these voyages and experiments the general inductions are, that between the Caribbee

Islands and the Coast of Guayana, in the months of August, September, and October, the Current veered to the Northward of N.W., and in other months more Westerly, or even to the Southward of West, as in November and December, 1834; but we learn, also, that the greatest velocity of Current has been observed in August and September, when the Marajion is at its lowest level, as well as in December and March, when this river begins to increase, and attains its greatest height ; even on examining the details, in order to discover any regularity in its force, we find an irregu- larity reconcileable only with that of the wind; and, more generally, by applying the theory of Trade Winds, and their influence upon the surface water of the Ocean.

After having once rebounded from the Brasilian Coast, the united Equatorial and Ethiopic Currents are again compelled to retire Westward by the influence of the S.H. Trade Wind (apparently, also, by the dispo- sition of the waters in these regions to retire Westward) ; and, although at passing the Marajion, which disembogues towards the N.E., the com- bined Current may, in some degree, according to its variable form and strength, derive an impulse to the Northward, yet it soon yields to the force of the N.E. Trade Wind, and the South-Westerly Drift thereby pro- duced, which sets toward the Caribbee Islands.

In proportion to the force and extent of these winds, the general current is pressed toward the shore of Guayana, as in December, 1835, and November and December, 1834; or allowed to expand freely to the North, as in August, September, and October; even to the N.E., as in March, 1837, especially when preceded by long and violent indraughts, and followed by calm weather. .

By the influence of the Maranon waters, the general Current is pre- vented from sweeping the coast to the Westward of Cape North; as the stream of this great river, being unobstructed, seems to gather all its strength, and force the Western boundary of that gigantic drift to an un- certain distance from shore. In this manner we may account for the weak Westerly Current, creeping along that part of the coast comprehended be- tween the Marafion and Gulf of Paria, called the region of the tides, and which is produced by the remaining effluxion of the Marafon, confined between the Western border of the general Current and the muddy banks of Guayana. It is incorrect to fix this border in 9 fathoms, as I have found it in twice and thrice that depth ; but, on the other hand, I think that if what has been supposed by Admiral Cosmé de Churruca should ever happen again - I mean the destroying of the Equatorial Current by the action of the rivers - the Atlantic will be found of a whitish hue, so far as these Currents shall reach, because their thick muddy waters never mingle with those of the ocean until they have been subdued by, and are at rest with them.*

* The great force of the Marajion current was observed by Captain W. Code, in the current North, 18 miles. This current must be caused from the waters of the Riyer Maraiion. The water is not salt, merely brackish taste, the sea boiling and making a great noise, which I have found seldom to occur when the currents are strong. - «Meteorological Report," 1872, page 30.

(315.) H.M.S. Challenger (August 21st - September 6th, 1873) crossed the South Equatorial Current from lat. 3° 25' N., long. 15° W., 420 miles W.S.W. from Cape Palmas, to Cape San Roque; visiting on the way St. Paul's Rocks and Fernando Noronha. She found the Currents much as represented in the illustrative diagram, page 295, but having generally a greater velocity ; thus, in lat. 3° 25' N., long. 15° W., the Current flowed 9 miles to W.S.W. in the twenty-four hours. Thence she steered direct for St. Paul's Rocks, and in long. 17° 30' W. found the Current setting 23 - miles to the N.W. in twenty-four hours; in long. 20° W., 20 m. W.N.W.: W. by N.; in 29° W. (50 miles E.N.E. from St. Paul's Rocks) the high velocity of 39 m. to W. by N. was found; at 70 miles S.W. of St. Paul's Rocks, 29 m. W.N.W.; midway between St. Paul's Rocks and Fernando Noronha, 25 m. §.W.; near Fernando Noronha, 21 m. West: at 60 miles S.W. of Fernando Noronha, 27 m. N.W.; at 90 miles East of Cape San Roque, 30 m. W.N.W. ; and on the coast of Brasil the Currents were gene- rally found flowing to the N.W. and West, as far as 15° S.

The wind at the commencement of this passage blew from the §.8.E., but afterwards came more from the Eastward. At Cape San Roque its direc- tion was from the S.E., varying in force from 3 to 5 (Beaufort scale, see page 104). The temperature of the surface water observed in this passage varied from 77° to 78°. At a depth of 10 fathoms in the Eastern and cen- tral part of the region traversed, the temperature of the water was 78°, while near St. Paul's Rocks at this depth it was only 77°, and near Fer- nando Noronha only 75°. At 50 fathoms, in the central part of the district, it was 62° to 63°, and in the Western 67°. At 100 fathoms the tempera- temperature at 50 fathoms in the Western than in the Eastern part of the district, seems to indicate the banking up of the warm water to the West- waid by the prevalent wind.

(316.) On this Current the following is extracted from Mr. R. Strachan's remarks in the Meteorological Report, 1872 : -

The South Equatorial Current commences on the African coast, and seems to extend at times as far as to 3° N. lat., though more commonly here it is not found beyond 1° N. To the first meridian its rate is from 12 to 17 miles. It now extends generally to lat. 3° N., and maintains this limit to long. 25° W., during a course nearly West of over 1,500 miles, at rates changing from 26 to 12 miles per day. It now has a tendency to the N.W., and attains lat. 6° or 7° N., and, as a general result, maintains this limit until it reaches the coast of Brasil. Near the Equator the mean rate is less than 24 miles per day, and this becomes lower as the latitude in- creases, so that in lat. 5° N. its velocity is less than 18 miles. For nearly 300 miles from the coast of Brasil and Guayana the direction of the Current is affected by the land. Off Brasil, the rate is from 62 to 37 miles per day; off Guayana, it is from 31 to 24 miles. Having passed the 50th meridian, the Northern edge merges with the Westerly Drift of the North Equatorial Current, though in some months this is effected in longitudes more to tha Eastward, even so far as the meridian of 25° W.

(317.) Commander J. R. Bartlett, U.S.N., from examinations made in

the surveying steamer Blake, in 1879, concluded that '' the Equatorial Current, which sets directly against the Windward Islands, is by them and their connected ridges deflected Northward, and so following their outer edge passes around the Virgin Islands to the Westward and through the deep channel to the Northward of San Domingo." He suggests, also, that on reaching Cuba the current divides, a part flowing N.W. through the Old Bahama Channel, and a part through the Windward Passage between Cuba and San Domingo, and thus by Cape San Antonio into the Gulf of

He also remarks : - '' The. Current, always found flowing North along the BHastern side of South America, on reaching Tobago divides, part join- ing the Equatorial Current setting North along the chain of islands; the remainder following the coast-line of Trinidad and the Spanish Main, and so around the entire circumference of the Caribbean Sea, finding at last an outlet at the Mona Passage and Anegada Channel, to join the Equatorial Current on its way to the Gulf of Mexico."

Both these theories are quite contrary to that founded on later inves- tigations made in the same vessel by Lieutenant Pillsbury and other officers. Professor Alexander Agassiz, who accompanied Commander Bartlett, says : - '' In the present state of our knowledge it is. difficult to trace the path of the Equatorial water as it is forced into the Eastern Caribbean."*

(317.) Lieutenant Pillsbury states that, from his observations, the Current caused by the S.E. Trade Wind sets towards the Windward Islands with varying strength, and leaves the island of Tobago with a course about N.N.W., joining the current caused by the N.E. Trade 8.W. of Barbados. The united flow is then between the islands, the strongest being in the passage South of St. Lucia, and lessening in velocity in the passages to the Northward as the latitude increases. Beneath the Westerly surface current in these passages is an underflow setting out to the Kastward.

(318.) Bottles. - A bottle from the ship Patriarch, in lat. 12° 47' N., long. 24° 47' W., December 20th, 1884, was picked up afloat at Colon, February 1st, 1886. It had thus traversed a distance of about 3,500 miles in 408 days, or at the rate of over 9 miles a day.

A bottle, thrown from the steamer Patrician, December 12th, 1887, in at the rate of 15 miles a day. (See Drift diagram, page 297).

A bottle, thrown overboard off Pernambuco, Brasil, July 28th, 1885, was picked up on the beach at Little Cayman Isiand, West Indies, March Ist, 1888, where it had probably lain more than 2 years.

(319.) An example of an extraordinary velocity on the Northern edge of this Current,is given by Captain W. Code, ship Albion: 1857, from August 45° 59' W., experienced a Current of N. 72° W. 73 miles, although not the slightest rippling or agitation of the sea was visible.

* «Three Oruises on the United States Coast Survey Steamer /'/ahe, 1877 - 1880." by Ajexander Agassiz, 2 vols., 1888.

tound to have been N. 61° W. 108 miles. Surprising current ; measured log lines and log glasses which are correct, so EBete is no doubt that. oe current has carried the ship the distance saanh

(320.) We have previously mentioned (302) that the combined streams of the North and South Equatorial Currents impinge upon the Eastern side of the Caribbee Islands, and some part passing to the Westward through the channels between them causes the Westerly Drift through the Caribbean Sea, which is not so persistent as it is in the Ocean to the Kastward, as will be presently explained. We first give particulars of the currents in the channels between the islands, and then proceed to describe those within.

(321.) In all the passages of the Windward. Teal a Westerly surface inflow prevails to a greater or less extent, but in those on the Northern side of the Caribbean Sea there is no fixed current. In addition to this flow there is a large volume of water entering _ the ee from the break of the waves.

Mr. R. Strachan, in his observations upon the Meteorological Office Current Charts, 1872, states that the Westerly Current, which enters the Caribbean Sea, has a rate of 37 to 46 miles a day North of Trinidad, but the rate decreases in the other passages as the latitude increases, and in lat. 17° N. it is only 12 miles a day.

In Grenada Passage, between Trinidad and Grenada, according to the Spanish Derrotero de las Antillas, &., the Current has been found to set nearly West; on the South side half a point Southerly, and on the North side half a point Northerly, its velocity being from 1 to 14 and 2 miles per hour. Commander Heyerman, U.S.S. Yantic, January 28th, 1888, in pro- found a current of 23 knots an hour setting W. 1° 8.

Observations taken in February, 1889, by the United States Coast Survey steamer Blake, tended to show, however, that there was no per- manent Westerly current in this passage, but that the surface currents were variable, with an under-current setting out to the Eastward, at a considerable depth. This deep under-current was also found in the passages to the Northward. Between Tobago and Barbados the mean direction of the surface current was North, although the Trades were blowing with a force of 2 to 7 Beaufort Scale.

Between Grenada and St. Vincent, among the Grenadines, the Currents are devious; but the general inset appears to be W. by N.

In St. Lucia Passage, between St. Vincent and St. Lucia, the Current gets in from the Eastward, but runs more Northerly ; and within, on the

West, it has been found setting to the N.W. Its velocity was found to be greater here than in the passages more to the Northward, as already stated At some distance below the surface the Blake found a tidal current, below which the water set out to the Hastward.

In Martinique Passage, between St. Lucia and Martinique, the current has been found to run nearly North, but very variable on the Western side of Martinique.

The U.S.S. Kearsarge, on March 19th and 20th, 1889, to the South- Eastward of Barbados, found a South-Hasterly current, of 30 and 20 knots a day respectively ; on the 29th, between Barbados and Martinique, the current set due North, 10 knots in 14 hours ; and between Martinique and Santa Lucia, 4 knots in 1 hour, and 8 knots in 4 hours.

In Dominica, Guadaloupe, and Antigua Passages, there is usually a gentle Westerly current. In Dominica Passage, between Martinique and Domi- nica, it has also been found to run nearly North, and between Montserrat and Antigua N.W.

At the distance of about 60 miles, within (or Westward of) the range of the Caribbee Islands, and to the Virgin Islands, the Current has been found setting, in general, to the W.N.W., from 1 to 14 mile an hour. On the leeward side of the Virgin Isles devious currents are found, frequently to the South-Eastward. The same have been observed on the Western side of St. Christopher's, &c.

(322.) On the Northern coasi vj Haytt, and in the Windward Passages, there does not appear to be any general Current. On the North side of Cuba the case is nearly the same; but in the channel there is a regular tide throughout the year, subject, however, to certain variations.

In Anegada and Mona Passages, the Blake found irregular and weak tidal currents, with probably a slightly preponderating current out of the Caribbean Sea on their Eastern sides, and into it on their Western sides.

Other observers state that in Mona Passage, between Porto Rico and Hayti, the Current has been marked as frequently setting to the N.W., and we have instances of a set through to the §8.W.; but Captain Monteath, in February, 1816, when proceeding Southward toward Porto Rico, from lat. 934° to 22°, long. 64° to 65°, found the Current setting N.N.H. at the rate of 20 miles in the 24 hours; and he says, that off the N.W. point of Porto Rico it invariably sets from the Caribbean Sea to the North and N.N.H. On the Western side of the passage it set North, 2 miles an hour ; but there have been instances of an inset from the N.W.

In the Windward Passage, between Hayti and Cuba, the Blake found the currents to be the same as in Anegada and Mona Passages, but more decided in velocity, probably depending upon the strength of the wind.

In the Bahama Passages the Currents are devious; both weather and lee currents having been found. These, also, appear to be influenced by the tidal causes; for the tides are operative on the banks, and sometimes set

In Bahama Old Channel and St. Nicolas Channel the current has been found to run North-Westward and South-Eastward, its direction depend- ing mainly upon the prevailing wind. In Santaren Channel it is very weak and irregular.

(323.) Bahama Islands. - The following remarks by Captain W. C. Berry are extracted from Captain Maury's " Sailing Directions," 8th edition, vol. ii., page 19. He says : - '' Having had long experience in the trade between New York and New Orleans, I herewith furnish you with a few remarks on Winds and Currents. For the last six years I have commanded the ship Vicksburgh, constantly trading between these two ports. In making the passage out, after passing the Hole-in-the-Wall, I have fre- quently found a Current, from 1 to 3 miles per hour, setting to the Hast- ward through the N.W. Providence Channel, particularly after the wind has prevailed from the Westward a few days. This, no doubt, has been the cause of putting a number of vessels on shore among the Berry Islands. I have latterly made it a point to take the last bearings of the light on the Hole-in-the- Wall, and either haul up or keep off as I found the current ; generally running on a West course until quite down with Little Stirrup Kays, then steering W. by N.4N., by compass, if in the night, until I was up with the Great Isaacs."

(324.) Lieutenant G. C. Hanus, U.S.S. Enterprise, states that in No- vember, 1890, when off the Bahama Islands, a current of about half a knot an hour was found, setting W.N.W. Between Castle Island and Cape Maysi, Cuba, the current encountered was slight at first, setting to the Westward, but, on approaching Cape Maysi, and after sighting the light, a current was found of about 14 knot per hour setting to the Westward, and gradually decreasing in force until after the light bore West, when the current changed to the Southward and Westward with gradually diminished

(325.) Of the Currents in the vicinity of Anegada and the Virgin Islands, Sir Robert Schomburgk says : -

."¢Tt is well known that the Tropical Current, caused by the earth's rota- tion, sets to the Westward, and its grand movement in these latitudes is directed through the Caribbean Sea; but it is probable that a branch of it, turned aside by the North-Eastern coast of South America, sweeps along the Caribbean Islands to the N.W. till it reaches the Bahamas; and it is this branch which at present attracts my particular attention, and in proof of the existence of which I adduce the following remarks : -

'*' Vessels bound from America to the West Indies, and chiefly to St. Thomas's, frequently find themselves to the North of the Virgin Islands ; and this deviation from their intended course has but too often proved fatal, having brought them on the reefs of Anegada when they thought them- selves far to the Southward of that dangerous island. Nor can repeated occurrences like these be attributed exclusively to errors in the observations for determining the latitude, or to false reckoning."

The American brig William and Thomas left New York October 28th, 1829; made Bermuda on the seventh day after her departure, when, con- trary winds retarding her course, land was discovered in the morning of November 15th. According to reckoning, it was supposed to be St. Martin's, but it was fortunately known, on approaching, to be Virgin Gorda, or pro- bably, in the night, the vessel would have gone on the reefs oi Anegada.

The English brig Francis, bound from Nassau, in New Providence, to trinidad, cloudy weather having precluded an observation for several days,

was supposed to be far distant from Anegada; but making land in the evening, supposed to be St. Martin's, was wrecked at 11 p.m. on the reefs of Anegada.*

The American brig Lewis, bound from Philadelphia to St. Thomas's wa Maracaybo, and supposed on the day previous to be on the parallel of St. Thomas's, was wrecked on the South-Hastern reef of Anegada, April 9th,

During his continuance at Anegada, Sir Robert Schomburgk ee additional proofs of the existence of a North-Westerly Current. He found on the South-Eastern reef several buoys with tyer (coir) ropes attached to them, which appeared to have come from St. Martin's. On September 24th, 1831, after a severe gale, two buoys were found on the same reef, which had probably been attached to anchors on some ground to the 8.H.

On sounding between Virgin Gorda and Anegada, Sir Robt. Schomburgk threw the log every thirty minutes, and, taking bearings of some remark- able objects, the drift was found to be always Westerly; and the result appeared to be the same whether the tides set North or South. On one day he left his anchorage, and sailed 10 miles to the Northward of Anegada, where the boat was lowered, and rendered stationary by means of a kettle filled with stones, it being then Southern tide; in spite of which the log was carried N.W. by W. A similar experiment was made in the waters between Virgin Gorda and Anegada, with the advantage of anchoring ; and the set was always the same, the drift being nearly 1 knot.

The North-Western or ebb tide between Anegada and Tortola is much stronger than the flood to the 8.E.; undoubtedly from the circumstance that tide and current work the same way.

On these circumstances Sir R. Schomburgk observes, that the wind, from March to June, frequently blows from the South and S.E., and the velocity of the N.W. Current will be thus increased; in consequence of which, vessels bound during that time for these islands are more subject to error in their course than at any other period; and lighter bodies being more influenced by the currents than heavier ones, may be taken as the specific cause of the last remark.

(326.) The Rollers, or Heavy Ground Swell, off the North-Eastern portion of the Antillas, which has from time to time produced so much mischief, was first described by Sir R. H. Schomburgk, as shown in the Journal of the Royal Geographical Society, 1835, to which the reader is referred for a complete explication of the subject.

The phenomenon appears to be caused by the meeting and combination of the Drift from the N.E., and the Equatorial Current from the S.E. or E.8.H. It rises, rages, and subsides, says Sir R. H. Schomburgk, when the air is calm, when there has been no indication whatever of a previous gale, or even when light airs have, for a considerable period preceding, come from the Southward of East. The waves approach in gentle undu- lations, but suddenly swell against the shore, and break with the greatest

* A great quantity of cork shavings are annually washed ashore on the North side of Anegada. They are considered to be drifted by the Equatorial Current from the coasts of Spain and Portugal.

impetuosity. The rise takes place sometimes gradually, but more frequently quite unexpectedly, the waves reaching an uncommon height.

/ Aheavy "Ground Sea" is distinguished by something grand and sublime. The sea approaches in undulating masses, which suddenly rise to large ridges, crested with foam, and form billows that burst upon the beach with the greatest impetuosity ; the spray flying, where the waves dash against cliffs, often more than 100 feet high, attended with loud roarings resembling thunder, which subside into a rumbling noise, caused by the nodules and fragments of rock with which the breaker was charged when advancing, which on its retreat roll backward, and are again driven forward by the next surge. Wave then follows upon wave in quick succession, there being, apparently, only a short interval after the third. The sea, for many miles from shore, assumes a peculiar aspect, different tints of blue, from the lightest to the darkest, forming a strong contrast with the snowy foam of the breaking waves, when they strike against a hidden rock, or with the white line visible along the whole coast. The Hastern Bahamas, the North- Eastern coast of Jamaica and Hayti, but chiefly Porto Rico and the Virgin Islands, and, in a less degree, the Northern Caribbee Islands, are subjected to this Ground Sea.

It may be considered, as a rule, that whenever the wind gets to the Northward of East for a day or two, there will be a Grownd Sea on the Northern side of the islands. The friction of the wind on the surface of the water causes little elevations or ridges, which, by continuance of the force, gradually increase, chiefly when the wind sweeps over a great extent of water. Finding no resistance, and having sufficient depth to sink directly down, they proceed with the direction of the wind, and remain natural waves, until they meet repercussion from dashing against the shore, when they rise to an elevation much above their natural state.

The period when the Ground Sea sets in is generally in October, and it continues, though with some intermission, till April and May. The wind accompanying or preceding a Ground Sea is, generally, from the Hast of North; the waves are, therefore, propelled, more or less, in a Western as well as Southern direction, and the Bahamas, and even Bermuda, may escape, whilst the islands from Barbadoes to Porto Rico, but more particu- larly the latter and the Virgin Islands, receive their first impulse.

A Southern gale will likewise produce a heavy swell on the Southern side of these islands; and, during the gale of August 30th and 31st, 1833, this was felt with great violence on the Southern shore. But, generally speaking, ueither in force nor duration are these surges to be compared with those of the Northern side; the group of the Virgin Islands being protected, in this direction, by the Caribbee Islands or by the Colombian coasts, and not exposed to the swell of the main ocean.

To one who crosses during a severe Ground Sea, from the Southern side of Tortola to the Northern, where the breadth of the island is inconsider- able, the singular spectacle is afforded of the sea, which on the Southern side is perhaps ''as smooth as glass,' on the Northern shore tossing, foaming, and roaring, as if agitated by a severe gale. The effect is most curious, and if it were not for the warning that is heard long before the cause becomes visible, one might fancy the wand of a magician in action.

The Northern coast of Porto Rico is subjected to a Ground Sea, of scarcely less force, and which has had the same effect on its coast as that of the Virgin Isles. The old '' English Pilot" observes, that the sea along the North coast of Porto Rico '' beats sometimes very ragingly."' The force of the waves that batter against the cliffs on which the Morro stands is amazing; and any observer will admit that the spray is sometimes carried more than 100 feet high. It has been said that, several years ago, a brig, in consequence of carelessness, here became unmanageable, and was soon dashed to pieces against the cliffs, but few of the crew escaping.

(327.) Caribbean Sea. - Within or Westward of the Windward Islandy there is a prevailing Westerly drift, weak and uncertain in the Eastern part of the sea, but gradually increasing in strength to the Westward. This drift, passing from the Atlantic through the Caribbean Sea into the Gulf of Mexico to feed the Gulf Stream, is not nearly so constant nor so strong as might be argued, a priori, from the apparent magnitude of that mighty current. Not only is it inconstant even in the mid-channel, but it is diverted by local causes and land configurations into opposite directions as hereafter is shown to be the case along the Colombian coast and in tha great Bays of Guatemala and Honduras. It appears to combine with the Tides in some degree, especially about the coasts of Cuba, Jamaica, and

Upon referring to the description of the Guinea or Equatorial Counter- Current, as recited in pages 325 to 334, it is shown that it extends much tarther to the Westward, during the period when the sun is in Northern signs. The Western extension of the Guinea Current, coincident with the increase of the Belt of Equatorial Calms (75), page 152, and (83), page 158, may owe its origin to the same causes, hitherto almost unexplained, as those to which this uncertainty of the Westerly Drift across the Carib- bean Sea is owing.

Whether it is owing to the influence of the moon and the Tide, the effect of barometric variations and distant and local Winds, or of Temperature and the changes of the seasons, or of some hitherto unexplained effect of the earth's rotation, has yet to be argued. It is probable that hereafter a systematic examination of these apparently contradictory phenomena will lead to some important conclusions in the general subject of Meteorology.

(328.) Mr. R. Strachan, from his investigations, found the average daily Westerly drift in this sea to be about 20 miles. In the Spanish Derrotero de las Antillas it is stated that in crossing from the Southern coast, or from Cartagena, to the Northern islands, it has been discovered that from La Guayra to the Eastern pert of Hayti, on a voyage made in December, a difference of 106 miles to the Westward was tound during the seven days the voyage lasted.

(329.) Lieutenant G. C. Hanus, of the U.S.S. Enterprise, states that in November, 1890, when in the fairway of the Caribbean Sea, between lat. current was found to run about 14 knot per hour, setting about W.N.W.; * but, from this latter position the Westerly set was rapidly lost, and the next day a slight Easterly current was found, which gradually increased as the coast was approached near Colon.

(330.) Lieutenant A. H. Bisschop Greevelink, in cormmand of the Dutch Royal Navy brig Echo, 1833 - 1837, from his four years experience in these seas, came to the following conclusions:: - '' The direction of Currents ini the Atlantic is reconcileable with the force and direction of the Trade Winds, but the height of the water-level in the Caribbean Sea will some- times baffle every calculation both within and without the range of islands, as shown indubitably by experiments founded, not only upon the method of ascertaining Currents at sea, but also within sight of land, and obser- vations made on shore along the coasts. It has also been found that during calm weather, even with strong HKasterly winds, the Currents have some- times been running for days together to the Eastward, especially in the latter parts of January and July, when, by the then prevailing strong winds, the water is heaped up in a very uncommon degree, and the inner part of the Caribbean Sea, most probably overcharged, succeeds in re- establishing its equilibrium by forsaking the power of its wrathful driver. In this manner, I think, we ought to reconcile those circumstances men- tioned (314) by the illustrious Spanish commander, Admiral Cosmé de

'In the Caribbean Sea the force and direction of the Currents are more distinctly modified by the direction of the wind. With continual light winds and smooth water the Currents are generally weak, augmenting only in proportion to the increasing wind. This may serve as a proof that, among other less perceptible causes, under which they are governed here, Wind is the most powerful agent ; for the indraught through the channels appears plainly to proceed from the force and extent of the Trade Winds. In this sea, from the Windward Islands Westward, to 72° of longitude, the general direction of Currents, observed during our four years cruize, was N.W. and Westerly ; the weakest in October, November, April, and May; the strongest in December, January, February, and March, along the coast of Venezuela, and in July and August in the Northern parts; - but, in general, so much always depended on the force of the wind, that, with few exceptions, almost every voyage was affected by a force of current corresponding to that of the prevailing wind."

(331.) From Trinidad, Westward, and off the North side of the Leeward Isles, the Current has been found setting West and S.W. to the Gulf of Maracaybo ; thence 8.W. also to Cartagena. From Cartagena toward the Channel of Yucatan it has been found N.N.W., N.W., W.N.W., and N.W. by N., from 1 to nearly 2 miles, and then decreasing to 13 mile per hour. On these coasts it has also been found setting to the Eastward, as shown, in the following pages.

'¢Qn the Colombian (now Venezuelan) Coast,' according to the Derrotero de las Antillas, ''from Trinidad to Cape la Vela, the Westerly Current sweeps the frontier islands, inclining something to the South, according to the strait which it comes from, and running about 14 mile an hour, with little difference. Between the islands and the coast, and particularly in the proximity of the latter, it has been remarked that the Current at times runs to the West, and at others to the Hast. From Cape la Vela the principal part of the Current runs W.N.W.; and, as it spreads, its velocity diminishes. 'There is, however, a branch, which runs with the

velocity of about a mile an hour, directing itself toward the coast about Cartagena. From this point, and in the space of sea comprehended be- tween lat. 14° and the coast (the Bay of Guatemala), it has, however, been observed, that in the dry season the current runs to the Westward, and in the season of the rains, to the Hastward.

"On the, Mosquito Shore, and in the Bay of Honduras, no rule ca be given for the alterations of the Current. All that can be said is, at a good distance from land, it has generally been found setting towards the N.W."

(332.) The Baron Alexander von Humboldt, in describing his passage from Cumana, Westward, to La Guayra, said : - '' The general motion of the waters between the Tropics towards the West is felt strongly on the coast during two-thirds of the year only. In the months of September, October, and November, the Current often flows toward the Hast, for fifteen or twenty days in succession. Vessels on their way from La Guayra to Port Cabello have been known to be unable to stem the current that runs from West to Kast, although they had the wind astern. The cause of these anomalies is not yet discovered. The pilots think that they are the effect of some gales of wind from the N.W. in the Gulf of Mexico ; yet these gales are much more violent in spring than in autumn. It is also remarkable, that the Current to the East precedes the change of the wind. It begins to be felt, at first, during a calm ; and, after some days, the wind itself follows the Current, and becomes fixed in the West.' - Personal Narrative, vol. iii, page 378.

'says : - '' In the afternoon we perceived high land through the haze, and hauled up for it, wishing to make a point about 50 miles to windward of Santa Marta; but on getting inshore, we found that we were 7 miles to leeward of that place, the Current from the Hastward having been run- ning for the last twenty-four hours upward of 2 knots an hour; which agrees with Baron Humboldt's account, that the Current runs from 1} to 2 knots an hour, according to the force of the wind and season of the year. The natives say, that the moon likewise has a considerable effect on this Current, which, at the changes of new and full, runs to the Hast- ward for twenty-four hours.

'« Here I must caution all captains of ships navigating on this line of coast to allow for the Current, in general, at least 14 knot per hour on an average, with an increase in proportion to the strength of the breeze, and an abatement at the new and full moons; otherwise, vessels heavily laden, overshooting their ports, may lose as much as three weeks by having to stand away nearly to the Antillas before they can get sufficiently to wind- ward to gain the port they have missed; and even men-of-war run a risk of carrying away spars and masts in beating up.'' - Vol. i., page 52.

(334.) The following extracts from the J ournals of Lieutenant Greevelink will be found of interest : -

'In January, 1834, the Hcho, in crossing the Caribbean Sea, from Curacao to windward, experienced a drift of 40 miles to the West, and escaped only by running straight for the coast of Hayti, beating to wind- ward along that and the coast of Porto Rico, with the best success, and even assisted by weak Hasterly currents when near the shore. The wind

was from the E.N.E., sometimes blowing a gale; but, when sheltered by the land, the water was tolerably smooth.

''In December, 1836, the Hcho, then on her passage from Surinam to Curacao, with sharp breezes, found the Current sweeping through the channel between Tobago and Grenada ; and, farther on, along the Leeward Islands, with a velocity of more than 2 miles an hour to the W. by N.; but, in October, 1836, on the same route, with light wind and calms, the water ran for days together to the Northward, at the rate of only half a mile an hour.

'In March, 1836, the same vessel, from Curacao to La Guayra, with very strong winds, spent six days in beating up against a Current of 40 miles mean daily strength; and on April 8th left La Guayra for Porto Cabello, in the bight to the Westward, when, instead of making this passage in some hours, she had, during three days, to contend with light, variable, and even Westerly winds, and Currents to the N.K. 15 miles daily.

"The Baron von Humboldt's remark about the increase of the Currents near the Testigos proved true on our approach to the same islands, in December, 1835.* In the morning of the 12th, the longitude observed was 62° 45' 15", and the difference West in twenty-four hours appeared to be 32' 15"; shortly after, the cluster of rocks came in sight; and at noon, at the very moment that the sun passed the meridian, the 8.W. island, placed by Don J. F. Fidalgo in 63° 12', bore East, distance 1 mile, having run by log 20 miles to the W. 3 N.; so that, during these last four hours, the Westerly difference amounted to 8 miles, whereas, in former watches, it was only 54 miles.

'"' A similar circumstance, we have reason to believe, also takes place at other groups of this range of sunken islands, and near such capes as are low and reaching far out, so as to obstruct the motion of the water beneath, and thereby redouble the force of the surface current, as denoted by the many instances of shipwreck and carcases of vessels (sad admonishers of precaution) spread among these flat, barren rocks, and produced solely by the irregularity of currents, which baffle every calculation, even those of the coast traders.

'But this variety in the Westerly Currents here is not the only cause of danger. The total change in the setting of the Currents from West to Hast is of a nature which requires the utmost care and attention, as they not only occasionally happen with calms, but also sometimes with fresh breezes from the Hastward. One of the first mentioned instances, particularly remarkable, we observed during our passage in October, from Surinam, through the Channel of Grenada, toward Curagao. On the 7th and 8th, between the Island of Tobago and Cape Malapasqua, the water flowed to the N. by H. and N. by W., with a trifling force; when suddenly, on the oth, we had a difference of 17' 54" North, and 34' West; and, on the follow-

* The remark is as follows. The Baron, on approaching the Testigos, July 14th, 1799, says : - '' During a calm, the Current drew us on rapidly toward the West. Its velocity was 3 miles an hour, and increased as we approached the meridian of the Testigos, a heap of rocks, which rise up amid the waters."'

ing day, at the new moon, we were driven 11' 12" to the North, and 35' 54" to the Hastward of our supposed situation. This case was too singular not to excite our attention, as the high mountains of Caraccas showed us, almost hourly, the East or Westerly direction in which we were driven, the weather being perfectly calm, and the water constantly smooth, by which means we were able to verify our chronometrical observations, and to remove every doubt respecting the truth of so extraordinary a circum- stance, the result whereof was as follows : -

'"« By the Westerly Current we drifted in sight of the high land near La Guayra, and kept working up against the strong Easterly set the whole following day. On the 10th, from seven in the morning till four in the afternoon, we had 14 miles difference West, agreeing with the bearing of Monte Avila. From that time till six in the evening, when that mountain, of which we had lost sight for a moment by drifting to the Westward, again became visible, the water flowed again to the Eastward; and on the 11th, at six in the morning, with an observed latitude, and the said mountain bearing 8.E. by S., we were in long. 67° 21'; and this by calculation being 67° 47', we found a difference of 26 miles to the Eastward in sixteen hours. From this time till four in the afternoon, again 10 miles to the West; and from thence until the following morning, 22 miles Easterly difference. During the night we hove-to to the Southward of Caraccas Bay, Curagao, and were obliged to keep Little Cwragao in mind, as the Current was set- ting strongly to the Eastward.

'' Whether this flux and reflux were caused by the moon (then new), or by any other agent, I shall not attempt to determine. Indisputably there occasionally appear satisfactory reasons for ascribing to that luminary some influence over the Currents in these regions, and the above-mentioned case is probably one of them ; but, as Captain Livingston says on the subject, 'the Winds have a still more powerful influence.' Indeed, when roving in these seas, studying the 'Memoir' and the 'Colombian Navigator,' and enjoying the pleasure of reading all that science and skill have ever pro- duced in the description of these regions, we always meet with Captain Livingston's remarks as so many illustrations, and feel a continued increase of respect for so accomplished a navigator.

"'The reflux of the Current to the Eastward, for some hours daily, we had also occasion to observe, in January, 1834, near the coast of Hayti, Porto Rico, and even in the Atlantic, while working up with smart breezes, and even with very strong winds; and once, in May, 1835, a merchant vessel, steering for Curacao, with her mainmast broken, passed in thé night to the Southward of Buen Ayre and Little Curagao without seeing the land, being totally unacquainted with any existing Current, and consequently with her real situation. At daybreak, finding herself opposite the Kastern part of Curacao, and supposing it to be the Island of Buen Ayre, she stood to the West for Curacao, as she thought ; but on her passing the Harbour of St. Anna she guessed her error, and tried to gain the entrance, in which she succeeded toward sunset, after hard struggling with a strong wind and a rough sea, but assisted by a Current to the Eastward.

"Tt should be borne in mind that the captain of this vessel was unpro- wided with a time-keeper, from want of which he knew nothing about

Hasterly or Westerly Currents; and if, on his approaching Buen Ayre, he had accidentally stood a few miles to the N.W., so as to make its Northern coast, he would have found a watery grave, designated, perhaps, only by some piece of floating timber, a splinter, or broken spar.

'The uninterrupted Easterly Currents alluded to have already been mentioned by Baron A. von Humboldt; and, whenever I witnessed them, T found them just as described by that celebrated traveller. It may, how- ever, be remarked that although this change in the general motion of the water is most common in the three months quoted, and chiefly along the Colombian coast, yet sometimes it also happens in other months, and in other parts of the Caribbean Sea; as we, in fact, once experienced it in December, once in April, near the coast above mentioned, and once in March, on our passage from Guadaloupe to Barbadoes, during whieh, vessels from St. Vincent's made their way toward the same islands in a few hours."

(335.) Observations taken in February, 1889, by the officers of the United States Survey steamer Blake, showed that South of Curagao the current generally ran to the Westward on the surface, and to the Eastward under- neath, but the under-current is of such volume that it is lable at times to entirely overcome the surface set.

(336.) In the Bays of Guatemala and Honduras, the Currents are fre- quently found to be running rapidly from West to Hast, especially near the shores. This counter-current is seldom encountered outside the lines which join their outer points. From Cape la Vela, or Northward of the Bay of Guatemala, the Current generally sets to the N.W. toward the Channel of Yucatan, as before remarked.

'In the space between Cape Gracias 4 Dios and Cape de la Vela, off- shoots and eddies from the great Equatorial Current are found. This assertion is not merely grounded on those of former navigators, or on the examination of the coast outline, but on actual experience.'' - Captain

(337.) Mr. Town, in his " Directions for the Colombian Coast," has said : - '' Although between the Island of Jamaica and the Spanish Main, Westerly Currents are most frequent, yet they do not always prevail; for ships have been known to be driven by the Current from 50 to 60 miles to the Hastward in four or five days. From the beginning of May till No- vember (the Rainy Season), the sea-breeze seldom or never blows home to the Main; and. ships going there should never go to the Southward of latitude 11° until they are at least 40 or 50 miles to the Westward of their intended port; after which they make a South course, as the land-breeze, which is generally from the 8.W., and the strong Hasterly Current, will set you to the Eastward of your intended port; if great care be not taken. When to the Eastward, if light winds prevail, you must stand to the North- ward until you meet the sea-breeze, which will lie between the latitudes of 10° and 11°, and then run to the Westward.

'"« Being off Porto Bello, in H.M.S. Salisbury, on August 12th, 1816, and being a little to the Eastward of that port, with light variable winds for several days, the ship was set to the Hastward, at the rate of 30 miles per day ; and, being afterwards placed in the same situation, I found it necessary

to make the land well to the Westward, and to keep close to it. From No- vember until May (the Dry Season) you should endeavour to make the land well to the Eastward, and run along shore; as the sea breezes generally blow very strongly, and the Current sets to the Westward at the rate of about 2 miles an hour.

Between Chagres and Porto Bello, during the rainy season, there is generally a Northerly Current, at the rate of 14 to 24 miles an hour. After the end of the rainy season the Current sets to the Southward and West- ward, and strong Southerly and Easterly gales prevail here. From No- vember until May (the Dry Season) the Southerly and Westerly are very light winds, except in squalls, which end with heavy rain.

"Tf at Chagres, at any time during the rainy season (May till November), and bound to the Eastward, endeavour to get 12 or 15 miles from the land as soon as you can; for the winds are, in general, very light, and the Current very strong. The latter sets from Chagres directly on the rocks of Porto Bello, and thence along the land K. by N., E.N.E., E.S.H., and according as the land lies; its general rate being from 14 to 24 miles an hour. Great care should be taken when near the land, if a heavy squall and rain appear to be coming on. During this you will have the wind from all points of the compass, and often so strong that all sail must be taken in.

"In crossing the Gulf of Darien, little or no Current will be found ; wherever there is any, it sets about South, S. by W., or S. by H., up the

"Near Cartagena the Current generally goes with the wind ; but off the Islands of Rosarito it sets to the N.W. and N.N.W., from 1 to 2 miles an hour. Between Cartagena and the Magdalena, in the rainy season, you cannot put any dependence on the winds or current ; but from November to May the Trade Wind blows home.

'«« T should recommend, if turning to windward, with strong Trade Winds, to keep the shore close-to; whereas, by going off from t4e land, you will not only have a heavy sea, but also a strong N.W. Current. If you have light variable winds, approach no nearer to the land than 12 or 15 miles, as you may be certain of an Hasterly Current."

Captain Livingston says : - '' During five weeks in which I remained at Cartagena, in June and July, 1817, the Current inshore set constantly and strongly to the Northward, at the rate, I am convinced, of not less than 14 mile an hour, or nearly as strong as the Mississippi at New Orleans. I have seen the Esk, sloop of war, current-rode against a very fresh sea- breeze, when at anchor, nearly West from the city, distant about half a

On July 31st, 1889, Captain Daniels, of the steamer Caribbean, between Cartagena and Colon, particularly off Farallon Sucio, observed the current to set E.N.E., 5 miles an hour!

Off Point Manzanillo, numerous tide-rips were observed from the U.S.S. Enterprise, in November, 1890, and a current of 14 knot per hour setting to the Eastward. Captain James Lockwood, of the Pacific Mail Steam- ship Company, states that he has often found a current close in to the coast as strong as 24 knots per hour.

As the land back of Manzanillo is high, and can be seen from 40 to 60

miles off, according to the state of the atmosphere, it forms a splendid landmark, and no allowance for the Easterly set is made by most of the captains of mail steamers, as, should the current happen to be slight, or no current at all be encountered, as sometimes happens, and allowance were made for the Easterly current, a vessel would make the low land to the Westward of Colon, where it is difficult to recognize.. By making no allowance, a vessel is sure to make the high land of Manzanillo or that between Manzanillo and Colon.

(338.) Captain Lima, of the Pacific Mail steamship Newport, stated, in 1891, that in ninety voyages from New York to Aspinwall he always made Farallon Sucio, off Cape Manzanilla, bearing S. by W. to S. by W. 4 W., even in the rainy season, when no observations could be obtained. His invariable rule is to change his course, so as to allow for the Easterly set near this coast, as soon as he sights logs, trees, and driftwood. At his speed of 12 knots he allows one-half to three-quarters of a point, according to the quantity of driftwood encountered. If the quantity of driftwood is very great, and the discolorization of the water very marked, he sometimes allows as much as 14 point. If he encounters no drift, he makes no allow- ance, and assumes that there is no current. - United States Notice to

Some remarks on this Easterly set will also be found on pages 148 - 149.

(339.) In the Bay of Honduras there is no permanent current, but out- side its limits it generally sets to the N.W. With respect to this, Captain W. J. Capes forwarded the following remarks to Mr. Purdy. He says : - '"« Between Jamaica and Bonacca the Current generally sets to the North- ward and Westward. Here, in May, 1816, I was set 60 miles to the West- ward by the Current, and found that it set rather Northerly, from one- quarter to half a mile an hour. Between Janiaica and Bonacca are the islands called the Swan Islands. I would not advise any one bound to the Bay of Honduras to make these islands, for it cannot be of service, and the current is so very irregular about them ; and by falling in with them in a dark night, a ship would be in danger of running on shore, as the land is very low. About the Southern Fowr Kays the currents are very uncertain. I have known three ships to be lost on these kays by lying-to for the night, after they have made them; for, at all times, the currents set strongly on them.

"Tf a ship be lying-to, under Rattan, it will not be amiss to try the Current. It is my opinion that the Current about Bonacca takes two different directions; one part setting to the N.W., and the other part branching to the §.8.W. I have found it so on several trials, which is the reason that I prefer taking a departure (for the bay) from the middle or Hast end of Rattan ; for, if a ship take her departure from the West end, her course will be N.N.W. (1816); but it very frequently happens that ships get down on the reefs of the Southern Four Kays when they take their departure from the West end. The reason is this - a ship steering N.W. from the West end has more of the Current on her beam, which sweeps round the end of Rattan very strong at times ; consequently, ships that take their departure from the East or middle part do not feel so much of the Current."

(340.) General Description of the Currents in the Bay of Guatemala, by Captain W. S. Smith, R.N. - Captain Mackellar, R.N., a writer worthy of great respect, remarks : - ''The Current between the island of Jamaica and the Spanish Main, or coast of Colombia, is not always to be depended upon as setting to the Westward, as is generally supposed ; for, in cross- ing from Jamaica to the Main, ships have been known to be driven to the Eastward by the Current." This circumstance must be of rare occurrence at the Northern part of the passage, and is here mentioned to make known its possibility. I myself have made runs across between Jamaica and the opposite Main at many times and seasons, and am, therefore, governed by practice as well as theory in the following remarks.

1. Local Current between the South side of Jamaica, the Morant Kays, and Pedro Shoals. - This is very uncertain, both in rate and direction. Its rate may be from 0 to 14 knot per hour ; and its direction, either North, East, or West, according to circumstances. At the Morant Kays, the Current is known to be variable. Over Pedro Shoals it is supposed almost ever to runin a Westerly direction. Between these two dangers, there- fore, it behoves a ship at night to be full of precaution, and not to rely on the continuance of any current she may have ascertained when either to the Northward or Southward of her then situation.

2. Current Southward of the Morant Kays and Pedro Bank, or between the parallels of 17° and 15°. This Current runs, perhaps always, true West to N.W. by W., from 20 to 55 miles per day.

Among the Mosquito Shoals the Currents are equally strong and more uncertain. Between latitude 15° and a line extending from Cape de la Vela to Cape Gracias 4 Dios, including some of the Mosquito Kays, the direction is W.S.W. to N.W., 20 to 40 miles per day.

3. In the Bay of Guatemala, Southward of a line between the Capes de la Vela and Gracias 4 Dios, and to the distance of 30 miles from the coast, the sets are so very variable as to baffle all system. Sometimes no current whatever is felt; at other periods it may run North, South, East, or West, 35 miles a day. Let it be borne in mind, however, that their direction is very seldom toward the Hast, but generally toward the West. St. Andrew's Isle and the frontier rocks of the Mosquito Bank are equally beset by changeable currents, of velocities amounting to fifty miles a day.

4. Between Cape Manzanillo, near Porto Bello, and San Juan de Nicara- gua, the Inshore or Land Current sets from Westward to Eastward. It is an eddy, striking out from the Westerly Caribbean Current at Gracias 4 Dios, and eventually returning into it, with a broken and divided force, to the North of Cartagena. The breadth of this Current extends from the land to a distance of about 30 miles in the offing. Its rate is from 1 to 2 knots, and its direction parallel to the curvature of the coast and capes.

The streams out of numerous rivers, entering this Current, seem to in- increase its rapidity ; for close inshore, between the rivers, the rate is seldom less than 2 knots; at 6 miles off the land it runs about 1 knot; and ata greater distance the same.

(341.) On January 9th, 1892, Captain Reynholds, of the barque Hévding, when in the vicinity of Morant Kays, states that his vessel was set out of her course 15 miles to the Northward by a strong Northerly current.

The United States directions say that the drift current, off Morant Kays, sets towards West and N.N.W., three-quarters of a knot an hour, after the Trade Wind has been blowing fresh for a day or two. When the Trade is lighter a current setting to the N.E. of Kast is frequently ex- perienced. Vessels having occasion to pass near Morant Kays at night should keep Northward of them.

In March, 1889, the steamer Blake, when between Jamaica and Hon- duras, to the S.W. of Pedro Bank, found the surface current running to S.W. by W., gradually changing to the Westward to a depth of 130 fathoms, and tidal below that depth. Between Pedro Bank and Jamaica a tidal or eddy current was found, setting to the Eastward.

(342.) From Cape Antonio, the western extremity of Cuba, the Current sets, at times, to the E.S.E., past the Isle of Pines. Captain Livingston informed us that, in March, 1818, he found the current between the Great Cayman and Isle of Pines to set in that direction, at the rate of fully 24 miles an hour, or 60 miles in the 24 hours. In August, 1817, he found the set nearly the same, but the Current not half so strong. The Spanish '« Derrotero'' says : - '' From Cape de Cruz, on the South side of Cuba, it is noticed that there is a-constant Current to the Westward, with some inclination to the Southward or Northward, and which has been known sometimes to set 20 miles in a single day.'' In opposition to this the exact words of Captain Livingston are - ''I have twice experienced a strong Current, setting about E.S.E., between the Caymans and Isle of Pines ; and on the latter of these occasions both my mate and myself separately calculated it to set about about 60 miles per day, or 24 miles per hour. This, however, J incline to think is a very particular case, such as may but seldom occur. The winds at this time were light and Westerly. On the other occasion, so far as I recollect, it set about 12 or 14 miles per day only. All my papers on these subjects have been lost; but the first instance was too remarkable to be forgotten."

A further evidence of this is given by Captain Harry Miles, ship Illustrious. '' December 29th, 1858, in rounding Cape Antonio, I could not detect any current. At times I have found it strong to 8.H."

(343.) Off the South side of Cuba, between Cape Antonio and Cape Maysi, the current has frequently been found setting to the Hastward when the moon is increasing, or in her first two quarters. It is represented that it runs to the Eastward for a fortnight, and then to the Westward about the same time. Coasters from the Caymans commonly take advan tage of the Easterly Current for making their passage to Jamaica.

From this information we may conjecture that the Current, which has been described as setting to the E.S.H. from Cape Antonio to Cape Maysi, is not permanent, but, at times, on the contrary, imperceptible, according to the age of the moon; and this has, we believe, been verified, in several instances, while the cause has remained unknown.

Captain Manderson stated, that when a strong Hasterly wind has been blowing between Cuba and Florida, vessels heaving-to off the South side of Cape Antonio, at about 6 miles from the shore, have, in the course of one night, been carried against a strong sea breeze, nearly as high as Cape Corrientes, being a distance of 80 miles. Captain Rowland Bourke, once

when lying-to in the Archibald, for the night, off Cape Antonio, also found himself, next morning, off Cape Corrientes.

Captain Monteath stated: - ''In the months of May, 1814 and 1815 (two voyages in which I was chief mate of the ship Prince Regent from Kingston) ; in June, 1817, in the ship Fame ; and in April and December, 1820, in the ship Mary; between Grand Cayman Island and Cape Antonio, I invariably found the current setting strong to the Eastward, or E.S.E.; and I have heard it generally remarked that vessels shaping a course from the Caymans for Cape Antonio have found themselves off, or even to the Eastward of, Cape Corrientes: this has, in the above cases, invariably happened to myself."

Captain Dunsterville has said, ''I am firmly established in an opinion, from twelve years observation, that not only are the Winds and the Weather on the West India station influenced by the change of the moon, but the Currents also; and it is frequently found that, if the waters run to the Eastward, it is at the change and full of the moon.'

On this subject Captain Livingston says, 'It is a prevailing opinion with many, that the moon governs entirely the Currents among the West India Islands. No doubt the moon has some effect on them, but the Winds have a still more powerful influence.

'"' Tt is rarely, indeed, on the North side otf the island of Jamaica that there is a Westerly Current when the North and N.W. winds prevail ; the Current then always, or almost always, sets to the Hastward.

'' On the South side of Cuba, when the wind is Westerly, which it often is, you are always certain of a reflowing current round Cape Antonio. This is easily accounted for; as when the fresh Trade Wind ceases, and the Westerly wind sets in, the barrier, which confined the waters in the Mexican Sea, is in some degree removed, and they seek to regain their level as well by the Channel of Yucatan as by the Strait of Florida."

Between the Isle of Pines and the main land of Cuba is a strong North- Easterly indraught, generally running from 1 to 14 mile an hour, and which has caused the loss of many vessels on St. Felipe Kays and the dangerous bank stretching therefrom to the Westward.

In the Windward Channel of Jamaica, the Current generally sets with the wind to leeward or 8.W.; yet both here and at Jamaica it is variable. Some have affirmed that, when a Current runs to leeward on the South side of Jamaica, there is frequently one setting Eastward on the North side; and, at other times, no current is to be perceived; also that, when a lee current runs on the North shore, the same circumstances may be perceived on the South shore as were before observed on the North.

(344.) Current Bottles - The following records, though old, of the drift of Bottles within the limits of the Caribbean Sea, will prove of interest : -

Caribbean Sea to Yucatan. - A Bottle from H.M.S. Chanticleer, in lat. 15° 29', long. 76° 8', to the Southward of Jamaica, at noon February 23rd, 1831, was picked up on April 20th following, upon the Eastern coast of Yucatan, after having traversed a distance of nearly 700 miles, at the rate of 28 miles per day.

Serranilla to Yucatan. - A Bottle from a boat belonging to H.M. surveying-ship Thunder, ab anchor under Serranilla West Kay, March 10th, 1884, was picked up

at Half-Moon Kay, in the Bay of Honduras, on the 23rd of the next month, April ; 'ate 10 miles per day.

Tobago to the Cayman. - A Bottle from the American brig Emma, June 17th, August, upon the Eastern shore of the Grand Cayman; distance 2,000 miles, at the rate of 28°6 miles per day.

Windward Channel, between Jamaica and Hayti. - A Bottle from H.M.S. Thunder, a knot; was picked up in the Grand Anse, near Jérémie (long. 74°1'), on the 24th of the same month.

Hayti to Florida. - A Bottle, from the ship Robert, Captain Coulter, Eastward of Alta Vela, on the South coast of Hayti, was picked up about thirteen months afterward on the shore near St. Mary's, in Florida.

Some Bottles enumerated in Captain Becher's list: Ship Racehorse, Captain 22nd, at Bonaire, 150 miles in 5 days. Ship Chanticleer, Captain Austen, thrown over February 23rd, 1831, in lat. 15° 30', long. 76°; picked up on the East coast of Yucatan, April 30th, 680 miles in 56 days. H.M.S. Thunder, Captain Barnett, thrown over at Chagres, April 22nd, 1840; reached Belize, October 1st, 1840. H.M.S. Thunder, March 10th, 1834, thrown over at Serranilla Bank; picked up near Belize, April 23rd; 575 miles in 44 days.

(345.) The Channel of Yucatan, connecting the Caribbean Sea with the Gulf of Mexico, is 105 miles in width, between Cape Antonio and Contoy Island, lying Eastward of Cape Catoche, the N.E. point of Yucatan. The Current most uSually sets with considerable rapidity to the Northward through it, and according to the calculation of observations derived from Major Rennell, Commander Maury, &c., the following is the mean rate of the Current in the various months : - January, 33 miles per day; February, 34 miles per day ; March, 36 miles; April, 33 miles ; May, 17 miles; June, 26 miles; July, 29 miles; August, 31 miles ; September, 30 miles; October, 38 miles; November, 36 miles; December, 48 miles per day. The annual mean of all these observations is 32:7 miles per day. 'These velocities are much inferior to what might be supposed from the magnitude of the outset of the Gulf Stream, as will be seen hereafter.

From the monthly results given in the Current Charts drawn up by the Meteorological Office, the annual mean is given as 33°9 miles per day. Mr. R. Strachan remarks : - The mean velocity of the Yucatan Current is 34 miles, but it flows into the Gulf of Mexico, towards N.W. by N., with a velocity of 41 miles; and at times the Current seems to be carried right across the Gulf. To the North and Hast there is no escape for it, owing to the Gulf Stream ; hence the check felt in issuing from the Yucatan Channel bears it off to the Westward, but not until it has attained its maximum strength in about lat. 23° N., long. 86° W. There are times, probably, when the Yucatan Current is weaker than the Gulf Stream ; then a counter-current, an overflow from the Gulf Stream, flows round Cape Antonio towards the Isle of Pines.

Captain Monteath stated as follows : - '' In my passage from Kingston toward Campeché, in the ship Fame, June, 1817, between Cape Antonio and Cape Catoche, I found the current to set due North, 27 miles, ina run of eighteen hours."

(346.) The Currents in this channel were carefully observed by the officers of the United States Coast Survey steamer Blake, in March and April, 1887. We here give the results of these investigations, as detailed by Lieutenant J. E. Pillsbury, U.S.N.

It was found that the Northerly current did not fill the whole channel, and the surface currents on either side were variable in their direction. On the Eastern side of the channel, within 20 miles of Cape San Antonio, there was a light but persistent flow into the Caribbean Sea, its direction varying according to the declination of the moon. At the time of low declination its direction was between N.E. by N. and E.S.E., the mean being N.E. by E.; at high declination it was between Hast and 8.E. by5., the mean E.S.E. The average velocity at 34 fathoms was only from 0:50 to 0°75 knot per hour. At high declination an eddy current was found setting from off Cape Antonio along the Colorado Reefs, but at 30 miles off shore it set to the Northward and Eastward.

On the Western side of the channel, in 23 fathoms, 5 miles inside the 100-fathoms line of Yucatan Bank, the interference of the stream current with the tidal current was very noticeable ; the flood tide running about N.W. for 18 hours, and on the ebb it ran to the Kastward.

In mid-channel the current varied but little from North, the average being N.E. by BE. The axis, or part of greatest velocity, was found to be West of mid-channel, with a bodily movement to right and left, according to the moon's declination. The velocity averaged about 2 knots, the maximum (about 3 knots) being experienced 10 hours before the moon's

The Blake was anchored at various distances between Cape San Antonio and Contoy Island, when the mean surface velocity of the Northerly current was as follows : - At 25 miles East of Contoy, 3°65 knots an hour ;

At the first position, which is 5 miles off the 100-fathoms line of Yucatan Bank, an extreme daily variation in speed of 3°95 knots was found at high declination of the moon. It is stated in the '" Annales Hydrographiques," 1889, page 236, that on one occasion it here attained a velocity of 6} knots an hour.

(347.) Gulf of Mexico. The Mexican Sea appears to be the receptacle and terminus of all the waters flowing Westward. It was formerly con- sidered that the Current through the Yucatan Channel diverging Hast- ward and Westward, the Western branch circulated around the whole of the Gulf to Westward and Northward, and thence flowing Eastward and South-Eastward, at rates varying from 14 to 31 miles per day, that it formed what was known as the '' Great Whirlpool ''* of the Mexican Gulf, and then joined the Eastern, and perhaps principal, branch of the Yucatan Current, torming the mighty Gulf Stream. Later investigations have shown that the general circulation of the water of the Gulf of Mexico is erratic in direction and feeble in force. Observations at twelve anchorages

Society, Philadelphia," vol. i., p. 250.

of the Blake, between the Mississippi Delta and Yucatan Bank, show a predominating direction to the Southward and Westward in the Northern half of the Gulf and close to Yucatan Bank, while between the two the flow is to the Hastward. The passage of water into the Straits of Florida ig sometimes from the Gulf and sometimes from the Yucatan Passage ; at high declination of the moon it is from the latter, and at low declination it is from the former.

(348.) In Captain Maury's 'Sailing Directions," 8th edition, vol. ii.,

There is a constant set from the Caribbean Sea into the Mexican Gulf to form the Gulf Stream, and vessels passing up to the Northward may take advantage of it. It is bifurcated just after entering the Gulf. The Bottle-paper of the Hermes followed this Yucatan Current to the ' fork," and then took the Western branch.

H. Congton, commander, J. EK. Solfleet, master. This Bottle, thrown over at the West end of Jamaica, was found on the South side of Padre Island, J. R. Butler, who says, 'The drift shown by the course of this Bottle confirms my own observations since I have been here, viz., that the Current divides between Cape Antonio and Cape Catoche, the Eastern part rounding Cape Antonio, and passing out by the Gulf Stream, while the Western part keeps a Westerly course until it reaches the coast between San Fernandino on the coast of Mexico, and Corpus Christi on Texas, where it meets the South-Westerly Current frem the coast of Florida and Louisiana. And it is strange to remark the mixture of floating objects thrown on the beach of this coast by the meeting of the Currents. Flat-boats, oars, saw-logs, clap-boards, old skiffs, &c., from the Mississippi, mixed up with branches of mangrove, mahogany, bay-cedar, young cocoa-nuts, canoe paddles of mahogany, &c., from the Caribbean Sea and Coast of Honduras.'

'"« Tt may be remarked on this that the Easterly winds may have some- to do with the Westerly drift from the Mississippi of objects which float high out of the water.

'« Another Bottle, from the ship Admiral, S. Picken, commander, thrown over on the Equator, long. 30° 45' W., February 17th, 1856, came ashore at Aransas Pass, Texas, October 24th, 1856, 250 days afterwards, having drifted 4,300 miles, or 16 miles per day.''

(349.) It is difficult to define the separation between the Currents which pass Hastward and Westward to the Northward of the Yucatan Channel. It is certain that they set with considerable velocity to the Southward and South-Kastward over the Tortugas Bank, and also to the 8.H. from the Mississippi. Perhaps a line might be drawn from the centre of the strait to the mouth of the Mississippi, to the West of which it may be found that the streams have westing in them, and to the Hast of it that they set towards the Gulf of Florida.

(350.) Mr. R. Strachan, in his remarks upon the Meteorological Office Current Charts, 1872, says : - The waters of the Equatorial Current find a passage Westward and Northward round the Gulf of Mexico, and they

keep up a well-defined movement of its water. Probably, in or about lat. 27° N., long. 90° W., a considerable portion of the Current which passed through the Yucatan Channel finds its way into the Gulf Stream. Here- abouts it would appear that the Currents are intricate, and difficult to ascertain by a day's run, from their conflicting influence upon the ship's

(351.) In the Supplement No. 2, 1891, to the Sailing Directions for the Caribbean Sea and Gulf of Mexico, published by the United States Hydro- graphic Office, it states, the Current coming up through the Yucatan Channel, takes a general North- Westerly direction, and then runs North- ward to about the latitude of the Rio Grande. Thence it flows Easterly until off the Delta of the Mississippi, where it is diverted to the §.E., and continues on to the Straits of Florida. Off the mouth of the Rio Grande, and thence to Vera Cruz; anywhere within 100 miles from the land,a - Southerly counter-current is usually found. When off the mouths of the Mississippi, within about 50 miles from the shore, a Westerly current is . almost invariably encountered. This Current varies from 1 to 2 knots per hour, growing stronger as the land is neared, and must be allowed for by vessels approaching the passes. A strong, or long-continued Westerly wind, however, occasionally has the effect of neutralizing this current, and sometimes, though rarely, reverses it. A strong and long-continued Norther may have the effect of producing a general Southerly set all over the Gulf. In the centre of the Gulf there is seldom any current except in the case of a heavy Norther.

(352.) The following refers to the Currents on Tortugas Bank. Captain H. Miles, ship Illustrious, states : - '' April 16th, 1859, at noon, in lat. fathoms, bottom at first depth coarse white sand, with broken shells, and gradually becoming of a greenish hue as the water shoaled. The wind being shy from §.W., I anxiously anticipated the Current which Blunt assures us 'runs lively to the Southward along the edge of Tortugas soundings,' in lieu of which, by a series of first-class observations, verified on making Bush Kay Light, I ascertained the set N.N.E., 14 mile per hour, since striking soundings. In fact, coupled with former experience, I am convinced that, although during the influence of Northerly and Easterly winds, a S.E. Current of considerable strength most certainly exists, yet with a Southerly breeze it is not only neutralized, but, as in the present instance, may set in a contrary direction, or to N.H."

(353.) The mean temperature of the water of the Gulf of Mexico is pro- bably as high as any part of the Ocean, from several manifest causes, and hence it is, on the shores of this sea, that some of those nurseries of the Sargasso weed exist (292), which, torn from its habitat by the force of the current, &c., is drifted into that great central area of the Atlantic, to which it gives the characteristic peculiarity.

It is also probable that animal life is peculiar and abundant in these »bserved in the Mexican Sea shine with greater brilliancy (April) than I had noticed elsewhere; some of these were very large, and flashed like the vriming of a gun, sometimes at a long distance from the ship. I

observed that the little shining spiracies were confined to the sides of the vessel and her wake, and that the waves, when they broke into foam, did not (as in other parts of the ocean) sparkle.

'"' The colour of the water in the Sea of Mexico is of a dark indigo, darker or more intense than that of the ocean generally ; the colour of the sea in the Florida Channel is a fine blue, not so dark as that of the Sea of Mexico, or of the ocean generally."'

(354.) The following description of the Gulf Stream is founded ona Paper by the late A. G. Findlay, F.R.G.S.,* with which we have incor- porated much later information from various sources, but chiefly from the Reports of the United States Coast Survey.t There is much that is apparently contradictory in the observations of the various explorers, tending to show, that like most other terrestrial phenomena, this great Ocean Current is subject in its course to various vicissitudes, both in velocity and direction. The whole subject is fraught with many difficulties.

In the section on Passages to and from the West Indies, hereafter, are some remarks for the use of vessels being navigated within its influence, within and near the Strait of Florida.

(355.) The Florida or Gulf Stream has received more attention, has been the subject of more speculation, and has served as the basis of more theories than all the other Currents of the Ocean collectively. Although modern research, conducted with all refinement, in contradistinction to the imperfect observation of the passing seaman in former years, has shorn it of much of the grandeur and magnitude with which it was formerly invested, still it is a mighty and majestic Current, well worthy of ail the laborious investigation which the philosopher and mariner have bestowed upon it.

The investigations carried out by the United States Government sur- veyors have dissipated all preconceived notions of its enormous magnitude; these were commenced in 1845, and when the first reports on the nar- rower portion, at the commencement of the stream, were published, sub- sequent to 1855, they were so startling as to be received almost with incredulity. But the subsequent most careful measurements of its Depth, Velocity, Temperature, and other collateral features, down to the present time, have tended to confirm, to some extent, the statement first made by Commander Craven in 1855, that the narrowest is the shallowest part of

* See Proceedings of the Royal Geographical Society, vol. xiii., 1869, pp. 102 - 112, **On the Gulf Stream," by A. G. Findlay ; and the Journal of the Royal United Service Institution, vol. xiv., 1870.

t See the Annual Reports of the United States Coast and Geodetic Survey, especially that for 1890, Appendix 10 of which consists of a description of the Gulf Stream, by Lieutenant J. HK. Pillsbury, U.S.N., being an account of his explorations daring five yoars, when in command of the steamer Blake.

its course. From the numerous sections which have been examined, on lines transverse to its course, between the Caribbean Sea and the banks off Nantucket, we are enabled to calculate with some approach to exact- ness, what is the amount, velocity, and temperature of the volume of water which is transported by it into colder latitudes.

As these investigations have been made in the spring and summer months, the conclusions arrived at may be incorrect for the other seasons, though there are no good reasons for supposing such to be the case.

(356.) It may seem, therefore, somewhat surprising, that - in the face of its now known much smaller volume and much slower rate of travelling, and also of the well-ascertained interferences it has to encounter - a much more extended area should be claimed by some to be under its influence, than was considered to be when very much less was known of its real character. When Major Rennell's '' Investigation" was published in 1832, containing a digest of all that was then known, the conclusion was arrived at, ''that as a Current, it may be said to terminate at ordinary times at the Western side of the Azores ;" and this is the sum of all the arguments subsequently used, with the exceptions that Dr. Franklin, in November, 1776, on approaching the Huropean coast, was never appa- rently out of the warm water of the Gulf Stream; and that Colonel E. Sabine, in 1822, found an abnormal warmth of the ocean water in the Eastern part of the North Atlantic, which he attributed to the unusual strength of the Gulf Stream that season.

It was only after the acquisition of our comparatively exact knowledge of the Gulf Stream proper, between Florida and the Newfoundland Banks, that the argument was advanced - that it is the Gulf Stream, which, after Araversing the intervening space of the North Atlantic Ocean, transports

V the amenity of climate over the whole of the North-Western shores of Europe; and also that in entering the Polar basin, past and around Spitzbergen, it keeps an open sea there, and by its warmth maintains a constant circulation around the North Pole.

(357.) It was during active researches in the Arctic regions, when the progress and fate of Sir John Franklin and Captain Crozier, with their ships' crews, were involved in such profound obscurity, that it was claimed for the Gulf Stream to have volume and power sufficient to have vast influence in ameliorating the Arctic climate. The failure of every attempt to penetrate the mystery, which had been so zealously directed towards the channels West of Baffin's Bay prior to 1851 - 1852, led Dr. Augustus Petermann to examine into the possibility of reaching the neighbourhood of Behring Strait by the way of Spitzbergen and Novaya Zemlia, and the elaborate and most useful investigations he then carried on led him to the conclusion that the varied phenomena he then elucidated, the abundance of animal life, the temperature of sea and climate, and certain features in almost every department of physics, could only be attributed to a warm North-Easterly Current, which he considered was an extension of the Gulf

* See Parliamentary Papers on the Arctic Expeditions; Further Oorrespondence, &c.,

1852, pp. 142, et seq.; also Journal of the Roya! Geographical Society, xxii., pp. 118 - 128, on the Distribution of Animal Life in the Arctic Regions, by A. Petermann, F.R.G.S.

(358.) To this last conclusion we still firmly demur, as in previous editions of this book, subsequent to the time when we were first made acquainted with the true dimensions of the Gulf Stream proper. In saying this, it must be distinctly understood that the effects claimed for it on the Eastern side of the Atlantic are not for a moment questioned. There can be no difference of opinion as to the facts which Dr. Petermann and many others bring forward in the elaborate memoir which he published.* It is rather a question of nomenclature, for the connection between these phe- nomena and the Gulf Stream proper is not shown.

The facts are incontrovertible, but it is strongly affirmed that these effects cannot be produced or effected by the Gulf Stream as now known, or by any fluctuations in its character. A very much wider field of action must be brought to bear on the subject; and it is contended that this North-Easterly drift or indraught, along the Scandinavian coast, should have a distinct name, as being an independent Current, having its origin somewhere between the coast of Europe and the Great Banks, and pro- pelled Northward by the §.W. winds which prevail throughout the year on this part of the Atlantic, or by some greater cause. But in thus stating the case, it must be qualified in a degree by the fact that the Gulf Stream water forms a small part of this Current, but it is so cooled down and inter- mingled with the Arctic Current, that if any direct connection does exist, it is with both of these Currents, and that, perhaps, in an equal degree.

(359.) In the preceding Sections we have traced the course of the waters from the shores of Europe down to the great set or Tropical Drift, and thence through the Channel of Yucatan to the Western entrance of the narrow channel between the North shore of Cuba and the Florida Kays. Here may be said to be the commencement of the Gulf Stream as an inde- pendent Current, as it flows swiftly hence to the Hastward in opposition to its previous course, and then Northward through the Narrows between Cape Florida and the Bemini Isles. Keeping this direction with its high velocity and temperature, it is deflected to the N.E. by the form of the American coast ; then assuming a more Hasterly direction, and gradually spreading its warmer waters over a broader area, through an immense region of perpetual fogs rising from its tepid waters, it pursues its course with a gradually decreasing rate and temperature, until it reaches the

Southern part of the Banks of Newfoundland. At this part it encounters , /

the Arctic Current, which crosses its track and imports into it the influences ~ of an Arctic temperature ; owing to this, and the counteracting effects of an adverse current upon its diminished force and much decreased volume, it ceases to maintain its character as the Gulf Stream or an independent

(360.) History. - The Gulf Stream was known by its present name, and in its now known form, from very early times. The Northern Equatorial Drift was noticed by Columbus, September 13th, 1492, when in lat. 27° N., long. 40° W., and this is the first Ocean Current observation. In his sub-

* Geographische Mittheilungen, Gotha, Justus Perthes, vol. xvi., 1870, parts 6 and 7. This most valuable essay, with ample references, was translated for the United States Hydrographic Office.

sequent voyages, in 1502-3, he observed the strength of the streams in the Caribbean Sea.* The first voyage through the Gulf of Florida was that by Poncé de Leon, in 1512 or 1513, and this gave the first account of the Stream itself, and he named the present Cape Cafiaveral el Cabo de Cor- rientes, from the circumstance. Several other Spanish voyagers, about this period, also experienced its effects, especially the pilot Antonio de Alaminos, who sailed through it in 1519. In Mr. Kohl's exhaustive and most in- teresting Monograph,} these and very many other earlier voyages are noticed, and the whole history of the subject dilated on.

(361.) That excellent observer, William Dampier, in his "' Discourses on the Trade Winds," &c., published in 1690, page 105, gives the following

"And 'tis as probable that the current, which sets to leeward on all the coast from Cape St. Augustine to Cape Catoch, never enters the Bay of Mezico, but bends still to the Northward, till 'tis checked by the Florida shore; and then wheels about to the Hast, till it comes nearer the Gulph's Mouth, and there joyning with the soaking current that draws down on the North sides of Hispaniola and Cuba, passes altogether with great strength through the Gulph of Florida, which is the most remarkable Gulph in the World for its Currents, because it always sets very strong to the North. Yet, near the shores on each side this Gulph there are tides, especially on the Florida shore; and Ships may pass which way they please, if they are acquainted.

"Tt has formerly been accounted very dangerous to meet with a North in this Gulph; and for that reason our Jamaica ships, to avoid them, have rather chosen to go to the Kastward and pass through the Cacuses (Caycos) in the season that Norths do blow. The Cacuses are sands that lie off the N.W. end of Hispaniola. Those that went from Port Royal in Jamaica had good reason for this; for if a North took them at their going out, it would help them forward in their way, which, should they have been going towards the Gulph, it would obstruct them. Then besides, if a North take a ship in the Gulph, the wind blowing against the Current makes an ex- traordinary Sea, and so thick come the Waves, one after another, that a ship can't possibly live in it, yet of late they go through at all times of the Year, and if a North takes them in the Gulph, they put away right before the Wind and Sea, with a small head sail; yet the Current is then as strong or stronger than at other times, and forces them back, stern fore- most, against both Wind and Sea; for though the surface of the Sea is raised in Waves and driven violently with the Winds to the Southward, yet the Current underneath runs still to the Northward ; neither is it any strange thing to see two different Currents at one place and time, the super- ficial Water running one way, and that underneath running quite contrary; for sometimes at an anchor I have seen the Cable carryed thus by two

* He remarks: - 'I hold it for certain that the waters of the sea move from Hast to West, and that in passing this tract (the Windward Islands) they hold a more rapid course, and have thus carried away large tracts of land, and that from hence has re- sulted the great number of islands.' Recent observations do not seem to bear out this

+ Geschichte des SoHetroms und seiner Erforsohung. J.G. Kohl. Bremen, 1868.

different Streams, the under part having been doubled one way, and the upper part the contrary."'

It is, therefore, somewhat surprising that a claim should have been made for Dr. Franklin as the real discoverer of its nature and its warmth in 1770. The tale is this : - Being in London in that year, he was con- sulted by the Treasury as to why the Falmouth packets were generally a fortnight longer to New York than common traders were from London to Providence, Rhode Island? He therefore consulted a Nantucket whaler, who laid its course on a chart, and explained that the Rhode Island cap- tains, being acquainted with the Gulf Stream, avoided it, while the Fal- mouth commanders, being ignorant of it, were set back 60 or 70 (!!) miles a day by it. Without stopping to refute this altogether, which may be done by Dampier and his predecessors, it will be evident that something else than the Gulf Stream must have retarded them 60 or 70 miles a day in that latitude, if they were thus delayed.

(362.) Causes - We have already given some general remarks (248, 249) on the origin and causes of surface currents. There have been very many speculations as to the cause of this great river in the Ocean, but they were _ promulgated before there was any increase of knowledge upon which to found arguments, and, as said before, recent investigations have overturned most of those which have been advanced. It has been supposed that it runs out of the Gulf of Mexico from the superior level of that sea, and facts are not wanting for such an assumption. Captain Manderson, R.N., gave an opinion in his 'Examination as to the true course of the Florida Stream," that it was owing to the Mississippi and the floods from the other rivers falling into the Gulf of Mexico. It was still further argued that the velocity of the Gulf Stream might be determined by the floods from thes rivers. But Captain Andrew Livingston, in our earlier editions, overturned this hypothesis by showing that what is poured into the sea by the River Mississippi is not a three-thousandth part of the volume of the Gulf Stream. He thought that it might be accounted for by the motion of the sun in the ecliptic, and its influence on the Atlantic waters.

The effect of Temperature is also advanced as the prime mover ; in- creasing its heat, the water expands, and thus becomes higher than the cooler waters beyond it, and as the Gulf of Mexico has the highest tem- perature, here is the head water of the Gulf Stream on that account. Sir John Herschel says on this point : - ' Let us see what this declivity, formed by unequal temperature, would amount to. The Hquatorial surface-water has a temperature of 84° F.; at 7,200 feet the temperature is 39°, the level of which temperature rises to the surface in lat. 56°. Taking the dilata- bility of sea-water to be the same as fresh, a uniformly progressive increase of temperature from 39° to 84° would dilate a column of 7,200 feet by 10 feet (or 9:971 feet more exactly), to which height, therefore, above the spheroid of equilibrium (or above the sea level in 56°), the Equatorial surface is actually raised by this dilatation. An are of 56° on the earth's surface measures 3,360 geographical miles, so that (were the water to run direct North) we have a slope of 1-28th part of an inch per mile for the water so raised to run down. As the accelerating force corresponding to

such a slope (of 1-10th of a second, 0-1" of arc), is less than one two- millionth part of gravity, we may dismiss this as a cause capable of creat- ing only a very trifling surface drift, not worth considering, even were it the proper direction to form, by concentration, a current from Hast to West; which it would not be, but the very reverse." *

With regard to this, Lieutenant Pillsbury, U.S.N., states that the tem- perature of the Ocean in the vicinity of the Equator reaches 37° F., at a depth of about 1,000 fathoms, below which the changes are slight to the bottom. The surface has » temperature not far from 80°. The expansion of the water due to this change in temperature is about '005, which for the column of 1,000 fathoms would be about 30 feet, giving a grade from the Equator to the Poles of about -06 inch to a mile, an infinitesimal difference.

Professor Ferrel considers that the effect of a difference of Temperature in the water of the Ocean between the Equatorial and Polar regions is similar to its effect on the atmosphere. The initial effect, before motion ensues, is to raise the surface of the Ocean at the Equator above that of