ON THOROUGH-DRAINING. ?7 



soil. He alluded to the practice, wliicli lie said had existed 

 from time immemorial, of throwing" the land into ridg-es and 

 furrows, and showed that, by the soil being" washed from the 

 tops of the ridg-es into the furrows, the higher parts of the 

 field produced comparatively Httle crop — the best particles 

 of which the land was composed being- carried oti' into the 

 furrows, and then into some adjoining- stream. Whenever 

 they saw a large river running brown after a fall of rain, 

 they mig-lit be sure that the best part of the soil was being- 

 carried away, never to be recovered, until, in the course of 

 time, it might be thrown up from the bottom of the sea and 

 form land such as their carses ; but it was lost irrecoverably 

 to the present g-eneration. It was of great importance, 

 therefore, to lay hold of that part of the soil, and not to 

 allow it to be washed away. In thoroug-h-drained land, no 

 drop of water should run on the surface in any direction, but 

 should penetrate into the ground where it fell. By the aid 

 of diag-rams, representing- a section of the ground, with stone 

 and tile drains in it, the lecturer then explained the manner 

 in which the rain percolated throug-h the active soil, then 

 into the parts of the soil not in use, but which had been 

 stirred by the subsoil plough, and then along- the surface of 

 the subsoil, which had never been mechanically moved, into 

 the drains. He next explained, by the same means, the 

 action of the atmosphere upon the soil in thoroug-h-drained 

 land, in producing- cracks or fissures, so that water easily 

 found its way into the channels prepared for carrying' it off 

 the g-round. Wherever the land was drained, it was ne- 

 cessary that the hig-h ridg-es should be done away with, and 

 the land laid down perfectly level. Some people had an 

 idea that water, when it fell, immediately beg-an to find its 

 •way to the drains through the earth in the straig-ht direc- 

 tion ; but there was nothing- which drew it in any way but 

 g-ravitation ; and its natural action, therefore, was to descend 

 as straig-ht as it could g-o. When rain fell with g-reat force, 

 if it were allowed to run along- the surface, as it did on un- 

 drained land, it carried away the whole of the fine soil ; but, 

 in consecjuence of this system of draining-, the whole of that 

 valuable matter was left by the water in the soil itself. The 

 water began to clear near the surface, and before it reached 

 the point where it found its way into the drain, it was per- 

 fectly pure. No better proof could be given of the effective- 

 ness of draining, than to see the water coming from the 

 drains perfectly clear, which was generally the case. As 



