of the hands of a watch, about the periphery of a huge ellipse, whose limits of latitude may be considered as 20° N. and 40° N., and which is bounded in longitude by the eastern and western continents. The central space thus inclosed, in which no wellmarked currents are observed, and in the waters of which great quantities of the Sargasso or gulf weed are encountered, is known as the Sargasso Sea.

529. The Southeast Drift Current carries its waters to the northwest coast of Africa, whence they follow the general trend of the land from Cape Spartel to Cape Verde. From this point a large part of the current is deflected to the eastward close along the upper Guinea coast. The stream thus formed, greatly augmented at certain seasons by the prevailing monsoon and by the waters carried eastward with the Equatorial Counter Current, is called the Guinea Current. A remarkable characteristic of this current is the fact that its southern limit is only slightly removed from the northern edge of the west-moving Equatorial Current, the effect being that the two currents flow side by side in close proximity, but in diametrically opposite directions.

530. The Arctic or Labrador Current sets out of Davis Strait, flows southward down the coasts of Labrador and Newfoundland, and thence southwestward past Nova Scotia and the coast of the United States, being found inshore of the Gulf Stream. It brings with it the ice so frequently met at certain seasons off Newfoundland.

531. Rennells Current was formerly represented as a temporary but extensive stream setting at times from the Bay of Biscay toward the west and northwest across the English Channel and to the westward of Cape Clear. The most recent investigations fail to reveal such a feature, but disclose only a narrow current of reaction moving northward along the coast of France when the winds have forced the waters above the usual level at the head of the Gulf of Gascoyne.

532. Of the two branches of the Southern Equatorial Current which are formed by its bifurcation off Cape San Roque, the northern one, setting along the coasts of northeastern Brazil and of Guiana and contributing to the formation of the Gulf Stream, has already been described; the other, known as the Brazil Current, flows to south and west, along the southeastern coast of Brazil, as far as the neighborhood of the island of Trinidad; here it divides, one part continuing down the coast and having some slight influence as far as the latitude of 45° S., and the other curving around toward east.

533. The last-mentioned branch of the Brazil Current is called the Southern Connecting Current and flows toward the African coast in about the latitude of Tristan da Cunha. It then joins its waters with those of the general northerly current that sets out of the Antarctic region, forming a current which flows to the northward along the southwest African coast and eventually connects with the Southern Equatorial Current, thus completing the surface circulation of the South Atlantic.

534. There is another current whose effects are felt in the Atlantic. It originates in the Pacific and flows around Cape Horn, and will be described in connection with the currents of the Pacific Ocean.

535. CURRENTS OF THE PACIFIC OCEAN.-As in the Atlantic, the waters of the Pacific Ocean, in the region between the tropics, have a general drift toward the westward, due to the effect of the trade winds, the currents produced in the two hemispheres being denominated, respectively, the Northern and the Southern Equatorial Currents. These are separated, as also in the case of the Atlantic, by an eastsetting stream, about 300 miles wide, whose mean position is a few degrees north of the equator, and which receives the name of the Equatorial Counter Current.

536. The major portion of the Northern Equatorial Current, after having passed the Marianas, flows toward the eastern coast of Taiwan in a WNW. direction, whence it is deflected northward, forming a current which is sometimes called the Japan Stream, but which more frequently receives its Japanese name of Kuroshiwo, or "black stream." This current, the waters of which are dark in color and contain a variety of seaweed similar to "gulf weed," carries the warm tropical water at a rapid rate to the northward and eastward along the coasts of Asia and its offlying islands, presenting many analogies to the Gulf Stream of the Atlantic.

The limits and volume of the Kuroshiwo vary according to the monsoon, being augmented during the season of southwesterly winds and diminished during the prevalence of those from northeast. The current sets to the north along the east coast

arriving at the extreme southwestern point of Japan by a route to westward of the Sakishima and Nansei Shoto. A branch makes off from the main stream to follow northward along the west coast of Japan, entering the Sea of Japan by the Tsushima Kaikyo; but the principal current bends toward the east, flows through Osumi Kaikyo and the passages between the Tokara Gunto, and runs parallel to the general trend of the south shores of the Japanese islands of Kiushu, Shikoku, and Honshu, attaining its greatest velocity between Bungo Suido and Kii Suido, where its average drift is between 2 and 3 knots per hour. Continuing beyond the southeastern extremity of Honshu, the direction of the stream becomes somewhat more northerly, and its width increases, with consequent loss of velocity. In the Kuroshiwo, as in the Gulf Stream, the temperature of the sea water is an approximate, though not an exact, guide as to the existence of the current.

537. Near 146° or 147° E. and north of the fortieth parallel the Kuroshiwo divides into two parts. One of these, called the Kamchatka Current, flows to the northeast in the direction of the Aleutian Islands, and its influence is felt to a high latitude. The second branch continues as the main stream, and maintains a general easterly direction to the 180th meridian, where it is merged into the north and northeast drift currents which are generally encountered in this region.

538. A cold countercurrent to the Kamchatka Current sets out of Bering Sea and flows to the south and west close to the shores of the Kuril Islands, Hokushu and Honshu, sometimes, like the Labrador Current in the Atlantic, bringing with it quantities of Arctic ice. This is often called by its Japanese name of Oyashiwo.

539. On the Pacific coast of North America, from about 50° N. to the mouth of the Gulf of California, 23° N., a cold current, 200 or 300 miles wide, flows with a mean speed of three-quarters of a knot, being generally stronger near the land than at sea. It follows the trend of the land (nearly SSE.) as far as Point Concepcion (south of Monterey), when it begins to bend toward SSW., and then to WSW., off Capes San Blas and San Lucas, ultimately joining the great northern equatorial drift.

On the coast of Mexico, from Cape Corrientes (20° N.) to Cape Blanco (Gulf of Nicoya), there are alternate currents extending over a space of more than 300 miles in width, which appear to be produced by the prevailing winds. During the dry season-January, February, and March-the currents generally set toward southeast; during the rainy season-from May to October-especially in July, August, and September, the currents set to northwest, particularly from Cosas Island and the Gulf of Nicoya to the parallel of 15°.

540. The Southern Equatorial Current prevails between limits of latitude that may be approximately given as 4° N. and 10° S., in a broad region extending from the American continent almost to the one hundred and eightieth meridian, setting always to the west and with slowly increasing velocity. In the neighborhood of the Fiji Islands this current divides; one part, known as the Rossel Current, continues to the westward, following a route marked by the various passages between the islands, and later acquiring a northerly component and setting through Torres Strait and along the north coast of New Guinea; the other part, called the Australia Current, sets toward south and west, arriving off the east coast of Australia, along which it flows southward to about latitude 35° S., whence it bends toward southeast and east and is soon after lost in the currents due to the prevailing wind.

541. The general drift current that sets to the north out of the Antarctic regions is deflected until, upon gaining the regions to the southwest of Patagonia, it has acquired a nearly easterly set; in striking the shores of the South American continent it is divided into two branches.

The first, known as the Cape Horn Current, maintains the general easterly direction, and its influence is felt, where not modified by winds and tidal currents, throughout the vicinity of Cape Horn, and, in the Atlantic Ocean, off the Falkland Islands and eastern Patagonia.

The second branch flows northeast in the direction of Valdivia and Valparaiso, follows generally the direction of the coast lines of Chile and Peru (though at times setting directly toward the shore in such manner as to constitute a great danger to the navigator), and forms the important current which has been called variously the Peruvian, Chilean, or Humboldt Current, the last name having been given for the

the Peruvian Current is its relatively low temperature. The direction of the waters between Pisco and Payta is between north and northwest; near Cape Blanco the current leaves the coast of America and bears toward the Galapagos Islands, passing them on both the northern and southern sides; here it sets toward WNW. and west; beyond the meridian of the Galapagos it widens rapidly, and the current is lost in the equatorial current, near 108° W. As often happens in similar cases, the existence of a countercurrent has been proved on different occasions; this sets toward the south, is very irregular, and extends only a little distance from shore.

542. CURRENTS OF THE INDIAN OCEAN.-In this ocean the currents to the north of the equator are very irregular; the periodical winds, the alternating breezes, and the changes of monsoon produce currents of a variable nature, their direction depending upon that of the wind which produces them, upon the form of neighboring coasts, or, at times, upon causes which can not be satisfactorily explained.

543. There is, in the Indian Ocean south of the equator, a regular Equatorial Current which, by reason of owing its source to the southeast trade winds, corresponds with the Southern Equatorial Currents of the Atlantic and Pacific. The limits of this west-moving current vary with the longitude as well as with the season. Upon reaching about the meridian of Rodriguez Island, a branch makes off toward the south and west, flowing past Mauritius, then to the south of Madagascar (on the meridian of which it is 480 miles broad), and thereafter, rapidly diminishing its breadth, forming part of the Agulhas Current a little to the south of Port Natal.

The main equatorial current continues westward until passing the north end of Madagascar, where, encountering the obstruction presented by the African continent, it divides, one branch following the coast in a northerly, the other in a southerly direction. The former, in the season of the southwest monsoon, is merged into the general easterly and northeasterly drift that prevails throughout the ocean from the northern limit of the Equatorial Current on the south, as far as India and the adjacent Asiatic shores on the north; but during the northeast monsoon, when there exists in the northern regions of the Indian Ocean a westerly drift current analogous to the Northern Equatorial Currents produced in the Atlantic and Pacific by the northeast trades, there is formed an east-setting Equatorial Countercurrent, which occupies a narrow area near the equator and is made up of the waters accumulated at the western continental boundary of the ocean by the drift currents of both hemispheres.

544. The southern branch of the Equatorial Current flows to the south and west down the Mozambique Channel, and, being joined in the neighborhood of Port Natal by the stream which arrives from the open ocean, there is formed the warm Agulhas Current, which possesses many of the characteristics of the Gulf and Japan streams. This current skirts the east coast of South Africa and attains considerable velocity over that part between Port Natal and Algoa Bay. During the summer months its effects are felt farther to the westward; during the winter it diminishes in force and extent. The meeting of the Agulhas Current with the cold water of higher latitudes is frequently denoted by a broken and confused sea.

Upon arriving at the southern side of the Agulhas Bank the major part of the current is deflected to the south, and then curves toward east, flowing back into the Indian Ocean with diminished strength and temperature on about the fortieth parallel of south latitude, where its influence is felt as far as the eightieth meridian. A small part of the stream which reaches Agulhas Bank continues across the southern edge of that bank before turning to the southward and eastward to rejoin the major part.

545. Along the fortieth parallel of south latitude, between Africa and Australia, there is a general easterly set, due to the branch of the Agulhas Current already described, to the continuation of the drift current from the Atlantic which passes to southward of the Cape of Good Hope, and to the westerly winds which largely prevail in this region. At Cape Leeuwin, the southwestern extremity of Australia, this east-setting current is divided into two branches; one, going north along the west coast of Australia, blends with the Equatorial Current nearly in the latitude of the Tropic of Capricorn; the other preserves the direction of the original current and has the effect of producing an easterly set along the south coast of Australia.

546. As in the other oceans, a general northerly current is observed to set into

CHAPTER XXII.

ICE AND ITS MOVEMENT IN THE NORTH ATLANTIC OCEAN.

547. Vessels crossing the Atlantic Ocean between Europe and the ports of the United States and British America are liable to encounter icebergs or extensive fields of compact ice, which are carried southward from the Arctic region by the ocean currents. It is in the vicinity of the Great Bank of Newfoundland that these

masses of ice appear in the greatest numbers and drift farthest southward. The accompanying charts show the changeable area in which icebergs and field ice have been reported by mariners in the years 1904 to 1913 in the months of April, May, and June, when they occur in the greatest number.

The amount of ice and its location and movement are so variable from year to year, while the region occupied in its formation and transportation is so vast and so little under special observation, that no successful system of prediction has as yet been instituted. The most that can be said now is that after an exceptionally open winter in the Arctic we may expect the ice to come south earlier and in greater quantity. After such a winter the East Greenland current starts the ice stream around Cape Farewell from one to three months earlier, and this advancing of the season is reflected by a corresponding advance in the Labrador Current and on the Newfoundland Bank. The greatest calving at the glaciers of Greenland follows the breaking up of the shore ice, and hence the bergs also start southward earlier and with more freedom after an open winter.

In April, May, and June, from 1904 to 1913, inclusive, icebergs have been seen as far south as latitude 37° 50′ north and as far east as longitude 38° west. Exceptional drifts have occurred almost down to latitude 30° north, and between longitudes 10° and 75° west, in these months as well as during other seasons of the year. Between Newfoundland and the fortieth parallel floating ice may be met in any month, but not often from August to December. On the Great Bank of Newfoundland bergs generally move southward. Those that drift westward of Cape Race usually pass between Green and St. Pierre banks. The Virgin Rocks are generally surrounded by ice until the middle of April or the beginning of May.

548. THE ORIGIN OF THE ICEBERGS.-Most of the bergs which annually appear in the North Atlantic originate on the western coast of Greenland; a few come from the east coast and from Hudson Bay. A small but productive glacier in southern Greenland yields the bluish bergs which are so hard to see at night. The largest bergs come from the glaciers at Umanak Fjord and Disko Bay (Lat. 69° to 71°), and their height above water will rise to 500 feet; but as they lose in mass from that time forward, we can not expect to find them of such gigantic height when they finally appear near the Newfoundland Bank.

A huge ice sheet, formed from compressed snow, covers the whole of the interior of Greenland. The surface of this enormous glacier, only occasionally interrupted by protruding mountain tops, rises slightly toward the interior and forms a watershed between the east and west coasts, which is estimated to be from 8,000 to 10,000 feet above the sea. The outskirts of Greenland, as they are called, consist of a fringe of islands, mountains, and promontories surrounding the vast ice-covered central portion and varying in width from a mere border up to 80 miles. Upon the west side, below the parallel of 73° of latitude, it has an average width of about 50 miles and extends with little interruption from Cape Farewell to Melville Bay, a distance of something over 1,000 miles.

Everywhere this mountainous belt is penetrated by deep fiords, which reach to the inland ice, and are terminated by the perpendicular fronts of huge glaciers, while in some places the ice comes down in broad projections close to the margin of the sea. All of these glaciers are making their way toward the sea, and, as their ends are forced out into the water, they are broken off and set adrift as bergs. This process is called calving. The size of the pieces set adrift varies greatly, but a berg from 60 to 100 feet to the top of its walls, whose spires or pinnacles may reach from 200 to 250 feet in height and whose length may be from 300 to 500 yards, is considered to be of ordinary size in the Arctic. These measurements apply to the part above water, which is about one-eighth or one-ninth of the whole mass. Many authors give the depth under water as being from eight to nine times the height above; this is incorrect, as measurements above and below water should be referred to mass and not to height.

Bergs are being formed all the year round, but in greater numbers during the summer season; and thousands are set adrift each year.

Once adrift in the Arctic they find their way into the Labrador Current and begin their journey to the southward. It is not an unobstructed drift, but one attended with many stoppages and mishaps. Many ground in the Arctic Basin and break up there; others reach the shores of Labrador, where from one end to the other they continually ground and float; some break up and disappear entirely, while others get safely past and reach the Grand Bank. The whole coast of Labrador