Irrigation and water-supply : a practical treatise ... / by John Scott.

  • Scott, John.
Date:
1883
Catalogue details

Licence: Public Domain Mark

Credit: Irrigation and water-supply : a practical treatise ... / by John Scott. Source: Wellcome Collection.

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    PKEFACE. The full advantages of irrigation are best realised in dry tropical or semi-tropical countries, where rain falls only at long intervals. There, many a large tract of land, that is naturally barren and worthless, is, with this provision, seen to yield rich and abundant crops. In these countries irrigation is a commercial necessity, and large sums of money are profitably expended on it. In countries of Northern Europe, where the climate is humid and temperate, by far the largest outlay is incurred, not in irrigation works, but in draining lands which suffer from an excess of moisture. It can rarely be necessary, on such soils, except in periods of exceptional drought, to have recourse to the double and expensive process of subsoil draining followed by irrigation. Subsoil draining is in itself a protection against drought; and deep tillage and frequent hoeing and stirring of the surface soil are to some extent sub- stitutes for rain, in the cultivation of plants. Still, in a climate like that of Britain, where the rainfall varies from 15 inches or less annually in dry districts in dry years, to 150 inches or more in wet districts in wet j^ears, it would be strange if the extremes of drought and flood did not occasion, at different times and in different places, the need of irrigation as well as of drainage.