This section is from the book "Commercial Gardening Vol1", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
This plays an important part in the formation of soils. It sweeps over the surface, taking away the moisture from it, and in dry weather the fine particles of dust and grit are borne from one place to another, together with leaves, twigs, and other organic material. Fresh surfaces are thus laid bare again for the action of rain, frost, snow, etc.
----------Soil Temperature at I foot deep.
-------Soil Temperature at 4 feet deep.
Fig. 84. - Variation of Temperature in Clayey, Sandy, and Chalky Soils.
SALPIGLOSSIS (Three-fourths natural size).