388 PHYSICAL GEOGRArHY OF THE SEA, AND ITS METEOROLOGY. 



alone, as is generally supposed, but (§ 131) Ly the great 

 equatorial caldron to the west of longitude 35°, and to the north 

 of Cape St. Roque, in Brazil. The lowest reach of the 80^ 

 isotherm for September — if we except the remarkable equatorial 

 flexure (Plate IV.) which actually extends from 40^ north to the 

 line — to the west of the meridian of Cape St. Roque, is above its 

 highest reach to the east of that meridian. And, now that we 

 have the fact, how obvious, how beautiful, and striking is the 

 cause! Cape St. Roque is in 5° 30' south. Now study the 

 configuration of the Southern American Continent from this cape 

 to the Windward Islands of the West Indies, and take into 

 account also certain physical conditions of these regions : the 

 Amazon, always at a high temperature because it runs from west 

 to east, is pouring an immense volume of warm water into this 

 part of the ocean. As this water and the heat of the sun raise 

 the temperature of the ocean along the equatorial sea-front of 

 this coast, there is no escape for the liquid element, as it grows 

 warmer and lighter, except to the north. The land on the south 

 prevents the tepid waters from spreading out in that direction as 

 they do to the east of 35° west, for here there is a space, about 

 18 degrees of longitude broad, in which the sea is clear both to 

 the north and south: they must consequently flow north. A 

 mere inspection of the plate is sufficient to make obvious the fact 

 that the warm waters which are found east of the usual limits 

 assigned the Gulf Stream, and between the parallels of 30° and 

 40° north, do not come from the Gulf Stream, but from this gi'eat 

 equatorial caldron, which Cape St. Roque blocks up on the 

 south, and which dispenses its overheated waters up towards the 

 fortieth degree of north latitude, not through the Caribbean Sea 

 and Gulf Stream, but over the broad surface of the left bosom of 

 the Atlantic Ocean. 



727. The imrmest sides of oceans and the coldest shores of continents 

 in juxta-position. — Like the western half of the Xorth Atlantic 

 Ocean, the western half of every one of the three great oceans is 

 the warmer. The great flow of warm water in the North Pacific is 

 with the " Black Stream of Japan," on the Asiatic side ; in the 

 South Pacific it is with the Polynesian drift, on the Australian 

 side : opposite to these warm Pacific currents and on its eastern 

 side, are the Humboldt current in one hemisphere, and the 

 California current in the other — cold currents both. In the 

 South Indian Ocean, the warm water is with the Mozambique 



