Page:Popular Science Monthly Volume 7.djvu/219

This page has been validated.
FORESTS AND RAINFALL.
207

civilization promotes chastity, elevates woman, breaks down the barriers of hate and superstition between ancient nations and religions; individual energy, the influence of one over the many, becomes less and less felt, and the power of the people becomes stronger.

Civilization in itself cannot but be beneficial to man; that which makes society more refined, more intellectual, less bestial, more courteous; that which, cures physical and mental diseases, increases the comforts and luxury of life, purifies religions, makes juster governments, must surely be beneficial; it is the universal principle of evil which impregnates all human affairs, alloying even current coin, which raises the question. That there are evils attending civilization as all other benefits, none can deny, but civilization itself is no evil.

FORESTS AND RAINFALL.[1]

THE question of the influence of forests on the hydrology of a region is one that has been warmly discussed. Some men of science, Becquerel for example, hold that forests increase the amount of water received by the soil; while others. Marshal Vaillant among them, assert that forests diminish the quantity. Some savans, such as M. Mathieu, sub-director of the Nancy School of Forestry, have endeavored, by way experiment, to get together such facts as might, if they did not set the question at rest, at least clear up some points and supply a portion of the experimental data needed for a full explanation at some future time. M. Mathieu undertook to "determine the amount of rain-water received by the soils of two neighboring districts, one of them covered with timber and the other arable land; and to find out whether, in consequence of the covering of trees which intercepts the rain-water, the soil of the woodland is as abundantly watered as that of the open." His conclusion is, that timbered soils receive as much, and more, rain-water than the open country.

These experiments are of great importance; the results obtained are noteworthy, and, taken in connection with Becquerel's observations, seem to be decisive of the question. Still, in order to meet an objection that might be raised against this mode of experimenting, viz., the difficulty of finding two districts near to one another and fairly comparable, we have made experiments from another point of view, which confirm those made by M. Mathieu.

No matter how you select two neighboring districts, it is not easy to prove that they are absolutely comparable to one another. The amount of rainfall may be seriously affected by the altitude, and particularly the relative altitude; by the situation of the district; by the relief and configuration of the land in the surrounding country; and

  1. Translation of a communication to the French Academy of Sciences, by L. Fautiat and A. Sartiaux.