Page:Popular Science Monthly Volume 26.djvu/79

Rh moisture as it crosses the Mediterranean, strikes the mountains—Guyot said he had known this wind to melt six feet of snow in twenty-four hours), these torrent-channels are almost instantly filled with furious, short-lived floods, which often sweep off bridges, buildings, crops, and even animals and human beings, besides tearing up costly roads, and wash away a vast amount of precious soil from mountain-sides, where it is sorely needed, and deposit it in rivers and harbors, where it is a nuisance, and often a serious peril to navigation.

In their gullying and undermining rage, these torrents tear out stones and large rocks from the hill-sides, grind them up into gravel, and even fine sand, and ruin much fertile land upon which they spread this material.

Marsh, in his "Earth as modified by Human Action" (p. 272), gives Surell as his authority for the statement that "the fury of the waters, and of the wind which accompanies them in the floods of the French Alpine torrents, is such that large blocks of stone are hurled out of the bed of the stream to the height of twelve or thirteen feet"; and remarks that "the impulse of masses driven with such force overthrows the most solid masonry, and their concussion can not fail to be accompanied by the crushing of the rocks themselves." On page 273, note, he quotes Coaz ("Die Hochwasser im 1868," p. 54): "At Rinkenberg, on the right bank of the Vorder Rhein, in the flood of 1868, a block of stone, computed to weigh nearly nine thousand cwt., was carried bodily forwards, not rolled, by a torrent, a distance of three quarters of a mile."

But there is further mischief, which, as being more widely diffused, is less sure to be assigned to the true cause—the stripping steep land of its covering of trees:

1. There is the failure of springs, because water of precipitation, which should have been delayed upon the hill-sides by the roots, sprouts, mosses, fallen leaves, etc., which fill and cover the surface of the ground under a forest, till it could find the underground spring sources, runs off the bare slopes in a few hours. Dry springs mean parched pastures, small crops, and unprofitable husbandry.

2. The increased cost of buildings, bridges, furniture, and implements of all sorts, which are, in whole or in part, made of wood. A large item in the current expenses of railroads is the outlay for ties, which must be renewed frequently. Wood for fuel or structural uses is a prime necessity of civilized life; and, as it is bulky, its cost increases rapidly with the distance it must be carried to reach the consumer. Many countries have no stores of coal or peat, and must have wood, or be sorely stinted for fuel; that stinting is a waste of time, health, and vitality. Floods make the maintenance of roads difficult and costly, and so, of course, increase the expense of whatever