THE DEAINAGE OF GEASS LAND. 9 



a hot day with waterlogged soil. The more scorching the sun, 

 the colder the soil becomes immediately beneath the surface. 

 The sun will make the top crust feel warm to the touch, even 

 when full of water ; but force a plunging thermometer through 

 into the subsoil and it will be found intensely cold. The tempera- 

 ture cannot even be increased by rain, for warm water is never 

 known to descend naturally. The rainfall remains on the surface, 

 instead of sinking into the soil and raising the temperature in 

 addition to its many other benefits. When the sun's rays cease 

 to fall on undrained land the cold subsoil quickly brings the 

 surface to its own low temperature, and this rapid change gives 

 birth to the mists which in autumn are so famihar in the Fens and 

 in the valley of the Thames. Surely there need be no wonder 

 that under these adverse conditions the grass on badly-drained 

 land is late to begin growing in spring and early to cease in 

 autumn. 



An eminent German scientist has demonstrated that there 

 is an intimate connection between a warm dry soil and economy 

 in feeding cattle. Friable land absorbs more heat than land 

 which is saturated with moisture, and retains the heat for a 

 longer period. Upon the one animals lie warmer, especially at 

 night, than they do upon the other. Now a large proportion of 

 the food consumed by animals is utilised for the production of 

 the heat which is constantly dissipated from their bodies. It 

 follows that additional food becomes necessary to replace the 

 animal heat lost by the colder surroundings. 



Land which is properly drained comes under the iufluence 

 of another operation of Nature, to the great advantage of the 

 crops upon it. Water would, after it has passed through the 

 surface to the subsoil, be lost to plant-life, were it not for the 

 wonderful natural arrangement known as capillarity.^ As the 



^ Baron Liebig, in his Natural Latos ofHmbandry, thus describes the action of water 

 in a Btate of motion : — 



' If we regard the porous earth as a system of capillary tubes, the condition which 

 must render them best suited for the growth of plants is imquestionably this : that the 



