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left dry. As on the Pacific coast of the United States, the rainfall decreases rapidly from north to south, Sitka having a mean annual rainfall of over 110 inches, San Diego less than eleven inches, and Lower California being practically rainless, so also in Chile, in going from south to north (this being in the Southern Hemisphere), we note a very striking decrease in rainfall. The dominating causes in both cases are the same, and the seasonal occurrence likewise. At Ancud, on the island of Chiloe in southern Chile (lat. 41° 46' S., long. 74° 01′ W.), the mean annual rainfall is (roughly), between 100 and 125 inches; at Valparaiso (lat. 33° 01'S., long. 71° 40′ W.), it is between ten and twenty inches, and at Copiapo (lat. 27° 22′ S., long. 30° 22′ W.), it is less than half an inch.

It is to be expected that such great difference in rainfall should exercise an important control over the occupations of the inhabitants, especially over such occupations as are directly connected with agriculture. For where, as in the northern provinces of Chile, there is practically no rainfall, agriculture on a large scale is impossible, and vegetable life can only grow in those restricted localities where irrigation can be resorted to. On the other hand, in the far south, where the abundant rainfall is favorable to the growth of forests, we shall expect to find that lumbering plays an important part in the life of the people. In the region midway between these two extremes, where there is neither an excess nor a deficiency of rainfall, agriculture will naturally be profitable and will constitute the chief occupation. Our expectations in these matters we find fully verified. In southern Chile, up to about lat. 41° S., which includes the region of heaviest rainfall, there are extensive forests as yet hardly attacked by man, and lumbering and fishing are the chief occupations. In northern Chile, north of lat. 27° S., where the barren nitrate fields replace the green valleys and the vine-clad hills of the more favored districts further south, the nitrate industry and mining of various sorts are the chief and almost the sole occupations of the people. Between latitudes 27° and 41° S., over most of which region there is sufficient rainfall for the growth of crops, although irrigation is necessary in many parts, comes the agricultural zone proper. In the northern districts of this zone, where the rainfall is very small,

mining becomes of importance; and in the southern districts, near the zone of heavy rainfall, lumbering becomes one of the chief occupations. In this agricultural zone, cattle-raising is also an important occupation, large numbers of cattle being shipped to the northern parts, notably Iquique, where the lack of vegetation precludes the raising of herbivorous animals. Indeed the so-called "nitrate ports" have to import almost everything in the way of food, this fact furnishing a very pretty illustration of the control of climate over imports.

We must, of course, be careful in any such consideration as the present, not to over-emphasize the influence of climate, pure and simple, over human occupations. Other factors, such as the geological character and the present topography of a region, are often the controlling influences in determining what the occupations of the inhabitants shall be, although climate almost always plays an important part. Thus, for instance, the great industry of the Argentine, cattle-raising, is possible on the immense grassy stretches of the pampas, not alone because the climatic conditions there are favorable for the abundant growth of grass and for a sufficient water-supply, but because the recent even elevation of these young marine plains above sea-level has added to South America vast tracts over which numberless herds of cattle can roam. In northern Chile, to note another instance, it is the geological history of the region, combined with past and present climatic conditions, which determines the presence of the nitrate and other deposits that make these desert tracts of such great commercial value. The simple climatic fact of lack of rainfall at the present time makes agriculture, except on a small scale where irrigation can be employed, impossible in northern Chile. Were the rainfall more abundant, farming would undoubtedly become one of the chief occupations, but an increase of moisture would probably mean the destruction of the nitrate industry. This region, then, is one in which human occupation is peculiarly controlled by climatic conditions.

ROBERT DE C. WARD.

HARVARD COLLEGE OBSERVATORY, SOUTHERN STATION,
Arequipa, Peru, S. A.

GENERAL FEATURES OF THE CANADIAN

ROCKIES.

The Rocky Mountains of Canada constitute one of those comparatively new parts of our continent which have special interest by reason of the grandeur of the natural scenery. The completion in 1886 of the Canadian Pacific Road opened up this wilderness to tourists, since which time the mountains, forests, and lakes of British Columbia and Alberta have been the admiration of travellers from all parts of the world.

After entering the mountains from the flat plains of Assiniboia the railroad is almost constantly hemmed in by high peaks, or lost in the depths of gloomy canyons, throughout a distance of four hundred miles, till the Pacific coast is reached. Even there at the western border of the continent, the mountains appear to rise from the sea, while the land-locked bays and narrow fiords seem like flooded valleys in a sinking land. In this journey from plains to sea, the entire system of the Rocky Mountains is crossed, and the observing traveller will notice that there are in all four pretty well defined ranges. Of these the Coast Range and the Gold Range are nearest the sea, and are characterized by mountains of low or moderate elevation, generally covered by coniferous forests nearly or quite to their summits. The streams and large rivers have cut deep channels through the rocky strata, and have made gloomy canyons in the process, so that the country was formerly, and is now to a great extent, very difficult to traverse. It was here in these two ranges of British Columbia that the greatest engineering difficulties were encountered when the railroad was building.

The third range from the coast is the Selkirk Range, justly celebrated among mountaineers as the "Switzerland of America.” In this range the highest peaks attain an altitude of about 11,000 feet. The rocks are schists and quartzites of the oldest geological formations and have been carved out into domes and pyramids of striking forms and appearance. The valleys are clothed in a dark green covering, a dense coniferous forest of cedar, hemlock, spruce and pine. The humidity of the climate caused by the damp air currents from the Pacific passing over the lofty mountains, is the reason why these forests are so dense and luxuriant. In fact, the undergrowth of ferns, alder bushes and the prickly Devil's Club,

combined with the moss covered tree trunks here and there lying prostrate in the forest, offer an almost impassable jungle to the explorer travelling with pack-horses. The very great precipitation in winter accumulates in snow-fields of considerable area on the higher parts of the mountains, and from these reservoirs glaciers descend into the valleys to an altitude of 5,000 feet above sea level. The contrast in color and form between the dark green forests of the valleys, the pure snow and blue ice of the glaciers, and the brown or iron-gray cliffs of the higher peaks, gives an ensemble of mountain beauty and grandeur comparable to that of the Alps or Caucasus.

The fourth and last range is nearly four hundred miles from the Pacific coast. Its mountains rise in sheer cliffs and escarpments direct from the plains and tower up in sullen walls of rock from three to five thousand feet above their bases. This range

of the Rocky mountains proper is frequently called the Summit Range. The highest crest forms the divide or watershed between the rivers that flow into the Atlantic and those that drain into the Pacific, and is also the boundary between the Canadian provinces of British Columbia and Alberta. These mountains are in many respects quite different from the Selkirks and the other ranges to the west. The mountains are higher and more rugged, reaching altitudes of nearly 12,000 feet; the snow-fields and glaciers are even more extensive than those of the Selkirks, while the forests are far less dense and the trees smaller in size. The nature of the rocky strata in the Summit Range is also much different from those of the other mountains. The rocks are sandstones, shales and limestones, disposed in very clearly marked layers, sometimes horizontal, but frequently tilted up at all angles and contorted in complex folds. Wherever the mountains are made of horizontal strata the weathering has produced curious natural monuments and sharp pinnacles of strange and fantastic forms, while very often an entire mountain resembles some ancient castle with towers and battlements, imitating in appearance the works of man with striking fidelity. Standing on a high elevation in this range, the mountains appear as long ridges of rock with very few isolated peaks, so that the general impression given by the successive ridges and valleys as one looks over a vast extent of country to a

distance of perhaps one hundred miles, is that of a stormy sea in which the mountains represent colossal billows.

Every one of the four ranges is made up a number of subranges, more or less distinct from each other, while even the subranges are divided into minor ridges of less importance and individuality.

Having now taken a brief review of the general features of the Canadian Rockies it would perhaps be well to make comparisons with other parts of the great Cordilleran System. This system in the latitude of Colorado is no less than one thousand miles in width. Extending too, from the center of Mexico. (for in recent years the mountains of Central America and the Andes have not been regarded as continuous with the Rockies of North America) to the Arctic Ocean, the very greatest diversity of climate and features naturally results in so vast a system. The lofty granitic domes of the Sierras and the barren summits of Colorado attain altitudes of more than 14,000 feet but the dryness of the climate gives little perpetual snow and nourishes but a scanty forest. Extensive areas of land exist the several ranges among of our Western States which have nearly the aridity and barrenness of true deserts where alkali ponds and salt lakes give proof of the small annual rainfall.

What could be in greater contrast to this state of things than the mountains of Alaska covered with perpetual snow, obscured by nearly constant fogs and clouds, and flooded by fields of ice and glaciers of vast extent? The Rocky Mountains of southern Canada have not the lofty grandeur of the St. Elias Range in Alaska nor of the Sierras in California, while their climate is a mean between the reeking humidity of the one and the desert dryness of the other. The Cordilleran System becomes perceptibly narrower as it runs northward from Colorado till at the International boundary it is only about four hundred miles in width. From this point on, the several ranges have a direction nearly northwest and southeast, or parallel to the Pacific coast.

Turning now to a consideration of the most important features of the Canadian Rockies in somewhat greater detail let us take up first the glaciers, rivers, and lakes of these mountains. As has been stated above, there are very extensive fields of snow in this

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