EUROPEAN AGRICULTURE. 



SEVENTH 11EPORT. 



CI. TILE AND PIPE DRAINING. (Continued.) 



ON this subject Mr. Parkes continues his remarks : &quot; The 

 phenomenon of a deep drain drawing water out of a soil from a 

 greater distance than a shallower one, is consistent with the 

 laws of hydraulics, and is corroborated by numberless observa 

 tions on the action of wells, &c. ; but the cause of the deeper 

 drain receiving more water in a given time, is not so obvious. 

 An opposite result, as to time, would rather be expected, from 

 the fact of water, falling on the surface, having to permeate a 

 greater mass of earth, both perpendicularly and horizontally, in 

 order to reach the deep drain. A natural agricultural bed of 

 porous earth resembles an artificial filter ; and it is unquestion 

 able that the greater the depth of matter composing such filter, 

 the slower is the passage of water through it. In stiff loams 

 and clays, however, but more particularly as regards the latter 

 earth, the resemblance ceases, as these soils can permit free 

 ingress and egress to rain water only after the establishment 

 of that thorough net-work of cracks or fissures, which is occa 

 sioned in them 3y the shrinkage of the mass from the joint 

 action of drains and superficial evaporation. These fissures 

 seem to stand in the stead of porosity in such soils, and serve to 

 conduct water to drains after it has trickled through the worked 

 bed ; it is possible, too, that, in deeply-drained clays of certain 

 texture, the fissures may be wider or more numerous, in conse- 



