Chapter 13

EFFECTS OF DRAINAGE UPON THE CONDITION OF THE SOIL.

Drainage deepens the Soil, and gives the roots a larger pasture.--Cobbett's Lucerne 30 feet deep.--Mechi's Parsnips 13 feet long!--Drainage promotes Pulverization.--Prevents Surface-Washing.--Lengthens the Season.--Prevents Freezing out.--Dispenses with Open Ditches.--Saves 25 per cent. of Labor.--Promotes absorption of Fertilizing Substances from the Air.--Supplies Air to the Roots.--Drains run before Rain; so do some Springs.--Drainage warms the Soil.--Corn sprouts at 55°; Rye on Ice.--Cold from Evaporation.--Heat will not pass downward in Water.--Count Rumford's Experiments with Hot Water on Ice.--Aeration of Soil by Drains.