Henry F. French,
Farm drainage
“ The effects of rain on drained soil, in the heat of Summer, are, then, two-fold; to cool the burning surface, which is, as we have seen, much warmer than the rain, and, at the same time, to warm the subsoil which is cooler than the rain itself, as it falls, and very much cooler than the rain-water, as it is warmed by its passage through the hot surface soil. These are beautiful provisions of Nature, by which the excesses of heat and cold are mitigated, and the temperature of the soil rendered more uniform, upon land adapted, by drainage, to her genial influences. ”
