1877
The influence of man upon climate has been a favorite subject of late years, and it is now well known that, by cutting down forests and draining the soil, men can materially change the climate of a country.
Some recent experiments conducted in Germany confirm this belief, by showing the extent to which woods will affect the rainfall. Two observatories were established for the purposes of comparison — one over a clump of trees forty feet high, and the other over a bare sandy plain about three hundred yards from the forest. Both observatories, were built at the same height from the ground. Twelve months' observation showed that of the total rainfall within that period ten per cent more rain fell over the trees than over the bare sand distant three hundred and thirty yards from them. Further, the air above the wood was charged with aqueous vapor to the extent of ten percent in excess of the air over the barren open soil. The ground too, under the trees, retained far more water than the exposed earth, evaporation from the surface, thanks to its shade of trees and moss, being only one-sixth of that outside their friendly shelter.
These results are valuable in that they point out a possible means of improving the condition of sterile tracts, i.e., by planting trees.
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