THE CLniATES OF THE SEA. 373 



heated up, not by the Gulf Stream alone, as is generally sup- 

 posed, but (§ 131) by 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 direc- 

 tion 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 flgw 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. Like the western half of the North Atlantic Ocean, the 

 The warmest sides of ^vestern half of overv one of the three sjreat oceans 



oceans and the . , rr^, *^ , ^ /. , • 



coldest shores of IS tho Warmer. 1 he great How oi warm water m 

 p'osmo"''"^'""" 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 cur- 

 rent 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 current on the African side, and 



