The Pacific slope, however, i5 an exception to this, its climate resembling the western coast of Europe much more than the eastern of its own. All the isothermal lines curve sharply northward west of the mountains. From Puget Sound to San Diego there is no extreme range of climate, no such division into quasi-Arctic and quasi-tropic as on the eastern slope; though the northern part from its heavy rains is the greatest timber region of the continent north, and ihe southern a great country of vineyards, almond orchards and other south-temperate products. California reaches from about the parallel of Boston to that of north Georgia and Mississippi, but has neither the raw, harsh New England climate nor the heavy southern atmosphere, and southern California is a noted warm sanatorium. The high arid plateau of north Mexico experiences extreme alternations of temperature, from 95° to 40° ; hut on the coasts and below the great Anahuac table-land the region becomes semi-tropic. Sugar-cane, cotton and coffee now ascend to the lower mountain regions, and in their place, at sea level, appear pineapples, bananas. etc. Central America from its narrowness and low elevation has an island climate, tropic and pestilential on the shores and along the streams, moderate and healthful on the higher ground in the interior. This and the Antilles are the region of sugar, indigo, cochineal, ginger, vanilla, capsicum, etc. South America, lying on both sides of the equator, has in the central and eastern parts a much less range of climate than North America, the greatest in a single section being found in Argentina, w here it is some 30°; over the whole continent the mean annual temperature ranges from 80° to 40°, the midwinter (our midsummer) from 80° to 35°, and the mid summer from 85° to ; north Argentina, the Cordilleran section, having,-as before, the great est alternations. The southern west Andean slopes are cooled and equalized by the west winds from the ocean; the northern parts are a tropic desert; but on the different levels of the range are found every climate of the earth from tropic to arctic. The tropic productions and characteristics south of the equator, except as deflected by local conditions, are much like those north of it. The zone reaching south as far as lat. S. has a mean temperature of 71° in the warmest and 53° in the coldest month. There the palm still thrives on the lower basin of the La Plata beside the mulberry and indigo; 'the pampas and the west coasts of Chile are characterized by beautiful araucarias (the pine of the southern hemisphere), by and oaks, the potato and the arrowroot. The plants in cultivation are a curious blending of the vegetation of the northern and southern United States: wines, olives, oranges, hemp, flax, to bacco, wheat, Indian corn and barley. The southern limit of the periodical rains reaches as far as lat. 48° S., when the mean temperature of 59° in the warmest and 39° in the coldest month still favors the growth of cereals, and on sheltered spots of the west coast the growth even of the vine and the finer fruits. The zone reaching to the southern extremity of America shows comparatively little difference between the warmest and coldest month, the mean tem perature of the one being 41° and of the other ; but the low degree of summer warmth pro duces a marked change in the form of vegeta tion which now presents only a few trees, as the beech and birch, and an extraordinary abun dance of mosses and ferns. As in passing from the equator to the pole the region of the veg etable world gradually declines, so in climbing from the tropical shores to the ice-covered mountain summits three different climates have been distinguished by the names of tierra caliente, templada and fria (hot, temperate, frigid). Of these the templada extends over those healthy and beautiful regions where .a kind of perptual spring prevails, and green pastures and noble forest trees are found united with the fantastical and gigantic forms of the tropics.
The question of rainfall is difficult to group systematically with that of climate. The mass
of the northern continent is in the region of the anti-trades or prevailing westerly winds. The Japanese Black Current, the Gulf Stream of the Pacific, running northeast and striking the polar currents and the cold shores, ice bound for many hundreds of miles, sends up a great steam of fog which is blown against the wall of the Rockies and sent back by them upon their western slope in a rainfall from 50 inches up to 100 or even more, that makes the northern coast from southern Alaska to northern Califor nia one gigantic forest of immense timber. The rainfall on Puget Sound is from 75 to over 100 inches in winter and the annual average on the Pacific coast of Alaska is 90 inches. In the southern part, along southern and Lower Cali fornia, the Cordilleran region above the Gulf and west Mexico, the same winds blow ; but the land is too warm to cool and precipitate the vapors to the same extent; and such pre cipitation as there is takes place mostly on the crests of the coast ranges, the Cordilleran re gion being mostly semi-desert or wholly so. In the summer the coast ranges are too warm to retain all the moisture of the vapors, which therefore give a little at these seasons, 10 to 20 inches in all, to the interior regions.
The Mississippi Valley is saved from be coming the most tremendous desert on earth, a second Sahara, by the Gulf of Mexico and the western wall combined. If it had to rely on the Pacific winds it would be utterly rainless; but these westerly winds in the Gulf region set up whirls of cyclonic disturbance which make an easterly eddy, carrying saturated currents in that direction; and these, striking against the Rockies, are turned northeastward through the central and eastern valley, giving it abun dant water. This eastward set, however, leaves the western valley only the edge of its course; the far western, as in western Kansas and Nebraska, being rainless for considerable periods and scantily supplied at best. The rainfall ranges from 60 inches on the coast to 30 around the Great Lakes. The same cyclonic move ment makes the same easterly eddy in the Atlantic, and the Atlantic coast receives its 40 to 50 inches a year from that source.
Central America is in the region of the trades or easterly winds and is so narrow that its climate is that of a semi-tropic island. In this region the rainfall is enormous, creating heavy tropic vegetation and increasing to 200 inches at Panama and the northwestern shores of South America, short rivers like the Atrato carrying almost a continental volume of water. All tropical South America is within the trade wind belt, its moist warm climate creating the enormous forests of the Amazon basin, the oceanic volume of that "river" (rather a huge set of parallel drainage channels in one vast swamp) and its tributaries, and the lesser but still mighty Orinoco. On the western slope of the Andes this portion receives no vapor and is a desert down to north Chile. But in central and south Chile and Argentina the anti-trades begin once more, and North American condi tions arc repeated: the westerly winds giving to that coast a mild, equable temperature and heavy rainfall, while the Andes bar nearly all the moisture from the east, and the great southern plains or pampas are a relatively arid steppe. , Taking the continent as a whole, the rainy none is disproportionately extended in America; and as it stretches over all the zones, the vege tation is remarkably diversified, from the lowly moss of the north to the lordly banana of the tropics. The giant chain of the Andes every where rises above the snow-line. From the sterile Peruvian coast, burned by tropical heats, one can look up to summits covered with per petual snow and ice; and one may climb from the gigantic equatorial vegetation of Quito to heights where only the condor testifies to the existence of organic life as he wings his flight over snow-fields and glaciers. In Peru the culture of cereals is carried on at the height of 12,000, and near Quito at 9,000 feet.