100 THE PRINCIPLES OF 



through the soil runs over the surface, and carries with it not 

 only fertilizing matter, but the finer particles of soil, and 

 deposits those finer particles in the open furrows, or at the 

 bottom of the slopes. Such soils are wet from top to bottom, 

 and if a trench is dug the ground is found comparatively dry, 

 and pipe-tiles would not convey any quantity of water from 

 such a soil in its then condition. 



I may quote a case which happened to my own father 

 when draining his land in the north of England. His friends 

 found fault with his method, and asked why he was draining 

 land, when the dry condition of the newly-cut trenches 

 gave very little indication that there was any overplus of 

 water. His reply was, " I drain the ground to get water 

 into the land as well as to get it out of the land." Such 

 lands, as we have already seen, offer a tremendous resistance 

 to the passage of water, and the action of the drain is in fact 

 at first very gradual. Drains upon such soils act slowly 

 at first, until, by their pulverizing action, they gradually 

 transform the soil into a more porous condition, and the 

 amount of work done by the drains gradually increases from 

 year to year. The pulverizing action begins close to the 

 drains, but it gradually spreads outwards on both sides and 

 especially above them ; it radiates from them until it meets 

 the action of the contiguous drains, which ought not to be at 

 too great a distance, let us say not more than twenty-one feet, 

 in which case ten feet six inches is all the distance that 

 the drain is required to act upon until it meets the action of 

 the adjacent drains. Putting these drains in at twenty-one 

 feet apart, the pulverizing action of the drain proceeds from 

 one drain to the other until it meets, and that no doubt is 

 the proper explanation of what is called the reciprocal action 

 of drains, which is a well-known term with reference to the 

 action of drains in clay lands. The idea of a reciprocal action 

 of drains has arisen from the fact that they appear to assist 



