128 THE PRINCIPLES OF DRAINING. 



peatedly liad to redraia land that liad been previously" 

 drained at shallow depths, and seen that the deeper drains 

 run first, tlie long-est, and discharg'ed the g-reatest volume, 

 and removed the cold damp from the surface, which the 

 shallower had failed to do. The practice of shallow drain- 

 ing- has arisen from the erroneous impression prevailing- that 

 their use is to take the surface water, and not to permit it to 

 first soak down, whereas no rain water should pass off the 

 ground, but all should be encourag-ed to g'o throug-h it, and 

 which, with proper tillag-e and drainage, it will do. Drains 

 are intended to prevent the return of water upwards, and 

 not to admit water from above. That draining- is so little 

 understood is hardly to be wondered at, when Ave consider 

 that until Mr. Parkes's attention was directed to it, the 

 practice had been g-enerally confined to tenant farmers, and 

 the advantag-es derived from extended experience and science 

 were unknown. I confess, until I had read Mr. Parkes's 

 essay on " The Temperature of Soils as affected by Drainag-e," 

 I was at a loss to g-ive satisfactory explanations for my 

 practice, althoug'h I had come to the same conclusion that 

 reading- his works will, I think, at once bring- every one. 

 To his works I v/ould refer all who are about to drain, for it 

 is a lamentable fact that by far the g-reater portion of the 

 money spent in draining- is comparatively lost, and as yet 

 few are aware of the full benefit to be g-ained. One of the 

 most important benefits to be derived from drainage is a 

 higher temperature in the spring of the surface-soil — a 

 benefit of extreme im])ortance in our climate, but which is 

 not fully attained by drains of less than 4 feet deep, and 

 scarcely felt at all when only 2^ feet. If rain passes 

 through the soil to the depth of 4 feet, the temperature of 

 the soil, by the passage of the water, is considerably raised; 

 whilst on the contrary, if drained only 2|- feet down, the 

 water from below is soaked upwards to the surface by ca- 

 ])illary attraction, and will be continually passing- off by 

 evaporation — this rise of water, and the effect of evapora- 

 tion producing extreme cold in the spring, appears too often 

 imknown. I have drained all descriptions of soil, and as yet 

 have never seen occasion to drain arable land less than 4 

 feet in depth, nor at distances less than 35 feet ; of course 

 the distance from 35 feet upwards will vary with the clia- 

 racter of the soil, the lighter requiring fewer drains; but I 

 take 4 feet to be the best depth for all soils, and the least 

 expensive. I pay dd. per rod for cutting- and laying and 



