PACIFIC OCEAN. 



PACIFIC OCEAN. 



mountains, with sides of remarkable steepness. Captain Fitzroy found 

 no bottom, within a mile and a half of Keeling Island, with a line of 

 : -at. The volcanic islands are of moderate extent, and generally 

 rise to a great elevation in their centre. Besides the different groups 

 which lie in a line along its western boundary, nnd which have been 

 already mentioned, several groups of volcanic islands are dispersed in 

 the ocean. The groups of this description north of the equator are 

 the Bonin Sima, Ladrone, and Sandwich Islands. The Galapagos 

 are traversed by the equator. South of the equator are the volcanic 

 groups of the Marquesas, Society, Navigator, and Friendly Islands, 

 and the solitary Easter Island. Some of these volcanic islands are 

 encircled by coral-reefs, as the Society, Navigator, and Friendly 

 Islands; others have not such a circle of reefs, as the Sandwich, 

 Ladrone, Bonin Sima, Galapagos, New Georgian Archipelago, and New 

 Hebrides. The islands which do not belong to the volcanic or lagoon 

 islands are few in number : the largest of them is New Caledonia. A 

 portion of the Pacific has a peculiar character. Flinders calls it the 

 ' Corallian Sea,' and determines its extent by assigning Papua and 

 Luisiade as its northern boundary ; whilst the north-eastern coast of 

 Australia up to Sandy Point (21 40' S. lat.) incloses it on the west, 

 and on the south * line drawn from Sandy Point to the Island of 

 Pines near the southern coast of New Caledonia. On the east it seems 

 to terminate at some distance from the New Hebrides. It extends 

 more than 1000 miles in length, and about 600 miles in width. The 

 whole space is covered with innumerable coral-reefs and banks, which 

 have only a few feet of water on them, and are very dangerous to 

 the navigator. This is probably both the largest and the most extra- 

 ordinary reef in any part of the world. It is divided from the continent 

 of Australia by a space of sea free from inlands, in general from 20 to 

 30 miles, and in some places from 50 to 70 miles wide. This arm of 

 the sea has generally a depth of between 10 and 20 fathoms, but this 

 depth increases towards the south to 40 and even 60 fathoms. 



Our knowledge of the winds and currents of the Pacific is far from 

 being so complete as that which we possess of the winds and currents 

 of the Atlantic. Still enough has been ascertained to make us 

 acquainted with the principal facts. 



The north-east trade-wind seems to be more regular than in the 

 Atlantic, and its northern boundary does not vary so much. From a 

 careful comparison of the observations of the most judicious navigators 

 made at different seasons, it appears that in summer toil wind extends 

 to 27 N. lat, in winter to 26' N. lat, and in spring only to 20 N. lat ; 

 and that from these limits it does not recede more than three degrees. 

 The southern boundary of the north-east trade-wind varies at different 

 seasons between 1 and 11 N. lat ; the mean boundary is between 5 

 and 6 N. lat 



The south-eastern trade-wind extends in winter to 254 s - !* an . d 

 in summer to 204 S. lat But according to numerous statements, it 

 appears that this wind is by no means so regular along its southern 

 border as in the Atlantic, and that it is frequently interrupted by 

 winds from the west and south-west The northern boundary of this 

 wind also varies considerably at different seasons and under different 

 circumstances : it may however be taken to extend generally in summer 

 to about 24 N. lat., and in winter to nearly 4 N. lat, while in autumn 

 it reaches beyond 54 N. lat In spring these winds recede to one 

 degree south of the equator. Captain B. Hall observes that towards 

 their northern boundary these winds blow from the south, but farther 

 south gradually draw more to the east, and at their southern limit 

 are quite easterly. 



In the Pacific the central line of the region of variable winds and 

 calm* is about six degrees north of the equator, but the boundaries 

 vary greatly ; it may however be said generally to range from 4 to 8 

 or 9 ' N. lat In passing this region the navigator meets with calms 

 interrupted by short squalls, and accompanied by a little rain. 



The south-east trade-wind U only met with from 300 to 400 miles 

 from the coasts of South America. In the intervening space the wind 

 always blows in the direction of the Andes from the south, changing 

 during the day a few point* to the west, and in the night freshening 

 off from the land. These wind* are always very light, nnd sometimes 

 interrupted by calms. North of Guayaquil the winds always blow 

 from the south-south-east, and are steady. 'The north-east trade-wind 

 is only met with at a distance of above 700 miles from the land. In 

 the tract of sea lying between their eastern limit nnd the coast dif- 

 ferent winds prevail in the different seasons. From June to November, 

 both included, the prevailing wind is from the north-west and west ; 

 it is very boisterous, and frequently comes in heavy gales and tornados 

 or furious squall*, which are accompanied by deluges of rain and most 

 dangerous thunderstorms ; they are sometimes interrupted by calms. 

 These winds set in earlier at the eastern parts of the isthmus than in 

 the western. At Panama they are expected in March, and at San Bias 

 in the middle of June. During this season the navigation along this 

 coast is very dangerous ; there are also few good harbours, and even 

 most of them are abandoned by the inhabitants on account of their 

 unhealthiness. In the opposite season, from December to May 

 included, the prevalent winds between Panama and Cape Blanco de 

 Nicoya are north-west and northerly, and they are pretty steady. 

 Frou/Cnpe Blanco de Nicoya to some distance east of Acapulco the 

 winds'blow from east and north-east, generally with moderate strength, 

 but they are sometimes interrupted by hard gales from the north-east, 



whicli are called Papayngos, and are experienced between Cape Blauco 

 (9 30' S. lat) and Cape Santa Catherine. They last for several days, 

 with a clear sky overhead and a dense red haze near t'.ie horizon. 

 Other gales of a similar description from the north sometimes occur 

 in this season east of Acapulco, opposite the isthmus of Tehuantepec, 

 whence they are called Tehuantepec gales. West of Acapulco, and 

 from 60 to 100 miles from the land, the winds are variable ; but the 

 prevailing wiuds blow between south-south-east and west-south-west. 

 Nearer the coast, land and sea breezes are met with, blowing from the 

 north-west during the day, and from north-east at night. They are 

 experienced also east of Acapulco to a distance of about 100 miles. 



The trade-winds also cease at a considerable distance from the 

 eastern coasts of Asia, and in the tract of sea bordering on these 

 coasts they are replaced by variable winds blowing generally from 

 north-west, south-west, and south-east. Along the coasts of Australia 

 the winds are very variable. 



In the region south of the trade-winds the weather and the turn 

 and succession of the winds are remarkably uniform. North-westerly 

 winds prevail, bringing clouds and rain in abundance. South-westerly 

 winds succeed them, and partially clear the sky with their fury ; then 

 the wind moderates, and blows from the south-east quarter, where, 

 after a short interval of fine weather, it dies away. Light airs spring 

 up from the north-east, freshening as they wear round to the north, 

 but soon shifting to the usual quarter, north-west ; and between that 

 point and the south-west they shift back sometimes for weeks before 

 they take another turn round. It never blows hard from east, rarely 

 with any strength from north-east, but occasional gales may be 

 expected in winter (between June and August) from south-east 

 Heavy tempests blow from west-north-west to south-west. In the 

 region north of the trade-winds the winds usually blow from the 

 south-west and west, and frequently in gales. When not strong they 

 are accompanied with heavy fogs. In the subordinate basins along 

 the coasts of Asia the Yellow, Japanese, and Okhotzk seas easterly 

 winds are rather prevalent 



We turn now to the Currents of the Pacific. Near the southern 

 polar circle a considerable portion of the surface of the ocean is in 

 motion at first towards the north, or north-east, and forms a current 

 of cold water known as the Antarctic Current, or Antarctic Drift 

 Current North of 60 S. lat it turns more to the east, and sets 

 towards the coast of South America, where about the parallel of Chiloe 

 it divides into two branches, the southern of which runs off southward, 

 and continues along the southern coasts of Tierra del Fuego to Cape 

 Horn westward, round which it passes with an average rate of a mile 

 an hour, and joins probably the South Atlantic Connecting Current. 

 This is known as the Cape Horn Current As the current sets rather 

 from the land, it diminishes the dangers which attend the navigation 

 along such a rocky coast But the current is not wide, and from 20 

 to 30 miles from the land it is hardly perceptible. The northern 

 branch of the Antarctic Current is known as the Peruvian or Hum- 

 boldt's Current, and runs northward along the western coast of 

 America as far north as Puuta de Parifia, or Cape Blanco (near 5 

 S. lat). The current extends about 1 00 miles from the coast, and is 

 of moderate velocity, generally not exceeding a mile an hour. It is 

 remarkable on account of the cold water which it carries from the 

 south to the north ; and it is doubtless to this current that Peru owes 

 its comparatively cool climate. The difference _of the temperature of 

 the water within the current and that of the surface of the ocean 

 without the current is considerable. At Callao the former indicates 

 62 Fahr., whilst in the same latitude, but about 300 miles from the 

 coast, the temperature of the sea is between 77 and 80 Fahr. From 

 the Punta de Parifia the current recedes from the coast, running off 

 in a north-western direction to the islands of Galapagos, enlarging in 

 width, but increasing in velocity to from 2 to 5 miles an hour. 

 Though the current has now reached the equator, its temperature has 

 not increased. Along the southern shores of Albemarle Island, one of 

 the Galapagos, Captain Fitzroy found that the thermometer immersed 

 iu the sea only indicated 60", while on the northern shores it stood 

 at 80. The low temperature of the water is believed to be the cause 

 f no coral-reefs being found about the Galapagos, the coral insects 

 being unable to sustain so great a degree of cold. From the Galapagos 

 the current runs westward towards the centre of the ocean, and 

 mingles imperceptibly, somewhere about 107 30' W. long., with the 

 southern portion of the great mass of inter-tropical waters, having a 

 constant westward motion, and known as the Great Equatorial 

 Current 



The Great Equatorial Drift Current flows on both sides of the line, 

 forming a belt 3000 miles wide. But it is divided into a southern and 

 a northern branch, which are separated by a counter current flowing 

 in the opposite direction. The southern branch, or South Equatorial 

 Current for it would be more correct to view the two so-called branches 

 as two distinct currents, has its southern limit about 26 S. lat. Its 

 general flow is north of west, and it has its greatest velocity towards 

 its western end. On its southern side among the Archipelagoes its 

 drift is considerably disturbed, in some places, as among the Feejeo 

 group and the Salomon Islands, it being diverted even eastward. A 

 portion of the current, which off the New Hebrides sets off strongly 

 to the north-west, is called Rossel's Drift by German geographers, but 

 it scarcely appears needful to regard it as a distinct current. The 



