148 THE PHYSICAL GEOGRAPHY OF THE SEA. 



CHAPTER YII. 



CURRENTS OF THE SEA. 



GoTcmed by Laws, ^ 396. — The Capacity of Water to convey Heat, 399. — The Red 

 Sea Current, 404. — The per centum of Salt in Sea Water, 418. — The Mediterra- 

 nean Current, 423. — Under Current from, 424. — Admiral Smyth's Soundings, 426. — 

 Lyell's Views, 429. — Admiral Smyth's Views, 436. — Currents of the Indian Ocean, 

 439. — Gulf Stream of the Pacific, 441. — Its resemblance to that of the Atlantic, 

 442. — An ice-bearing Current between Africa and Australia, 449. — Currents of the 

 Pacific, 451. — A Sargossa Sea in the Pacific, 452. — Drift-wood upon the Aleutian 

 Islands, 453. — Cold Ochotsk, 454. — Humboldt's Current, 455. — Warm Current in 

 the South Pacific, 456. — Equatorial Currents in the South Pacific, 458. — The Effect 

 of Rain and Evaporation upon Currents, 459. — Under Currents of the Atlantic, 461. 

 — Equilibrium of the Sea maintained by Currents, 467. — The Brazil Current, 469. 



396. Let us, in this chapter, set out with the postulate that the 

 sea, as well as the air, has its system of circulation, and that this 

 system, whatever it be, and wherever its channels lie, whether in 

 the waters at or below the surface, is in obedience to physical laws. 

 The sea, by the circulation of its waters, doubtless has its offices 

 to perform in the terrestrial economy ; and when we see the cur- 

 rents in the ocean running hither and thither, we feel that they 

 were not put in motion without a cause. On the contrary, reason 

 assures us that they move in obedience to some law of Nature, be 

 it recorded down in the depths below, never so far beyond the 

 reach of human ken ; and being a law of Nature, we know who 

 gave it, and that neither chance nor accident had any thing to do 

 with its enactment. 



397. Nature grants us all that this postulate demands, repeat- 

 ing it to us in many forms of expression ; she utters it in the blade 

 of green grass which she causes to grow in climates and soils made 

 kind and genial by warmth and moisture that some current of the 

 sea or air has conveyed far away from under a tropical sun. She 

 murmurs it out in the cooling current of the north ; the whales of 

 the sea teU of it (§ 70), and all its inhabitants proclaim it. 



