98 THE PHYSICAL GEOGRAPHY OF THE SEA. 



204. Commencing at this parallel of 30°, therefore, in the North 

 Pacific, and tracing thence the course of the northeast trade-winds, 

 we shall find that they blow thence, and reach the region of equa- 

 torial calms near the Caroline Islands. Here they rise up ; but, 

 instead of pursuing the same course in the upper stratum of winds 

 through the southern hemisphere, they, in consequence of the ro- 

 tation of the earth (§ 126), are made to take a southeast course. 

 They keep in this upper stratum until they reach the calms of 

 Capricorn, between the parallels of 30° and 40°, after which they 

 become the prevailing northwest winds of the southern hemisphere, 

 wliich correspond to the southwest of the northern. Continuing 

 on to the southeast, they are now the surface winds ; they are go- 

 ing from warmer to cooler latitudes ; they become as the wet 

 sponge (§ 177), and are abruptly intercepted by the Andes of 

 Patagonia, whose cold summit compresses them, and with its lo\7 

 dew-point squeezes the water out of them. Captain King found 

 the astonishing fall of water here of nearly thirteen feet (one hund- 

 red and fifty-one inches) in forty-one days ; and Mr. Darwin reports 

 that the sea water along this part of the South American coast is 

 sometimes quite fresh, from the vast quantity of rain that falls. 



205. We ought to expect a corresponding rainy region to be 

 found to the north of Oregon ; but there the mountains are not so 

 high, the obstruction to the southwest winds is not so abrupt, the 

 highlands are farther from the coast, and the air which these winds 

 carry in their circulation to that part of the coast, though it be as 

 heavily charged with moisture as at Patagonia, has a greater ex- 

 tent of country over which to deposit its rain, and, consequently, 

 the fall to the square inch will not be as great.* 



206. In like manner, we should be enabled to say in what part 

 of the world the most equable climates are to be found. Tliey are 

 to be found in the equatorial calms, where the northeast and south- 

 east trades meet fresh from the ocean, and keep the temperature 

 uniform under a canopy of perpetual clouds. 



* I have, through the kindness of A. Holbrook, Esq., United States Attorney for 

 Oregon, received the Oregon Spectator of February 13, 1851, containing the Rev. G. 

 H. Atkinson's Meteorological Journal, kept in Oregon City during the month of Jan- 

 uar}'^, 1851. The quantity of rain and snow for-that month is 13.63 inches, or about 

 one third the average quantity that falls at Washington during the year. 



