104 



why it should be introduced especially into tenacious soils. It re- 

 moves stagnant water, and renders tlie soil porous. It removes 

 the sources of evil and is the occasion of good by opening 

 the interstitial canals of the soil for the reception of air and health- 

 ful moisture. 



If you would drain tenacious clay soils effectively, reference 

 must be had to the season, as well as to the depth and nearness of 

 the parallel drains, and the main or discharging drain. The best 

 time is in the Summer, when the weather is dry. The drains, 

 after they are opened, should remain a few days before the pipes 

 are laid, and the ditch refilled. Such soils are usually of greater 

 intrinsic value than sandy soils, and require more skilful treatment 

 to make them produce well, especially in the art of draining. 



Concerning the depth of drains and their distance from each 

 other, there are various views and opinions entertained by expe- 

 rienced drainers. These may be accounted for in part by the dif- 

 ference in soils. It is no more strange that this should be so, than 

 that husbandmen should differ in reference to the depth of plough- 

 ing. Farmers are not generally informed as to the depth which the 

 roots of cereals and other crops penetrate. It is said the smaller 

 grains send down roots to the dcspth of three or more feet ; and 

 mangold-wurzel four or five feet. All good arable lands should 

 then be drained to the depth of three feet. To do this, the drains 

 must be sunk four feet deep from the surface. The interstitial 

 canals existing in the soil, have been compared to tubes, the down- 

 ward pressure being increased by the greater length of these. If 

 the drains are shallow, the tubes short, the pressure will be less, 

 thus draining more slowly. The truth of this doctrine is demon- 

 strated by practical observation ; for deep drains run sooner and 

 faster after a rain than shallow ones. Hence, the reason why 

 deep clay soils require deep draining in order to render it effectual 

 and beneficial. The theory of inexperienced reasoners on this 

 subject, is in opposition to facts. The theoretic objection to the 

 deep drainage of clay soils is as good, theoretically, against shal- 

 low as deep drainage, which is, that the water will not percolate to 

 the drain. 



Before drains can become effective either in deep or shallow 

 draining, the pores and interstices of the soil must be emptied of 

 the stagnant waters, that have filled them. This requires some 

 time. Where there are slopes or ridges on the surface to be 

 drained, the drains should be run across these at an angle of 45 

 degrees. 



Drains that were sunk to the depth of four feet after ten years, 

 have been found six or seven inches nearer the surface than when 

 the pipes were laid. Hence no thorough drainer should be con- 



