EAINS AKD EIVEES. 119 



ture is liiglier than its detv-jwint. We have a rainless region 

 about the Ked Sea, because the Eed Sea, for the most part, lies 

 within the north-east trade-wind region, and these winds, when 

 they reach that region, are dry winds, for they have as yet, in 

 their course, crossed no wide sheets of water from which they 

 could take up a supply of vapour. Most of New HoUand lies 

 within the south-east trade-wind region; so does most of inter- 

 tropical South America. But intertropical South America is the 

 land of showers. The largest rivers and most copiously watered 

 coimtiy in the world are to be found there, whereas almost exactly 

 the reverse is the case in Australia. Whence this difference ? 

 Examine the direction of the winds with regard to the shore-line 

 of these two regions, and the explanation will at once be suggested. 

 In Australia — east coast — the shore-line is stretched out in the 

 direction of the trades ; in South America — east coast — it is per- 

 pendicular to their direction. In Australia they fringe this shore 

 only with their vapour ; thus that thirsty land is so stinted with 

 showers that the trees cannot afford to spread their leaves out to 

 the sun, for it evaporates aU the moisture fi'om them ; their vege- 

 table instincts teach them to turn their edges to his rays. In 

 intertropical South America the trade-winds blow perpendicularly 

 upon the shore, penetrating the very heart of the country with 

 their moisture. Here the leaves, measuring many feet square — as 

 the plaintain, &c. — turn their broad sides up to the sun, and court 

 his rays. 



298. WJiy there is more rain on one side of a mountain than on 

 The ratxy SIDE OF the other. — We may now, from what has been said, 

 z^ouMAi.Ns. ggg ^^j j.^Q Andes*^ and all other mountains which 



lie athwart the course of the winds have a dry and a rainy side, 

 and how the prevailing winds of the latitude determine which is 

 the rainy and which the diy side. Thus, let us take the southern 

 coast of Chili for illustration. In om^ summer-time, when the sim 

 comes north, and drags after him the belts of perpetual winds and 

 calms, that coast is left within the regions of the north-west vdnds 

 — the winds that are counter to the south-east trades — which, 

 cooled by the winter temperatm-e of the highlands of Chili, deposit 

 their moisture copiously. During the rest of the year, the most 

 of Chili is in the region of the south-east trades, and the same 

 causes which operate in California to prevent rain there, operate 

 in Chih ; only the dry season in one place is the rainy season of 

 the other. Hence we see that the weather side of all such moun- 



