

IMPROVEMENT OF LAND. 89 



land; and wherever deep-ploughing has been put into operation after 

 the drainage, the land has been vastly improved, while in those cases 

 where the drainage has been done without deep-ploughing following it, 

 comparatively small advantages have been obtained from the operation. 

 There is a great variety of opinion in regard to the drainage of land, 

 some holding that drains of the depth of three feet, put on at from fifteen 

 to eighteen feet apart, are the most efficient for general purposes ; while 

 others have taken the opposite extreme, and recommended drains to be 

 made five feet deep, and from thirty-five to forty feet apart. But, generally 

 speaking, the most intelligent part of agriculturists adopt a medium 

 between these two extremes, and make their drains from three and a half 

 to four feet deep, and from twenty-five to thirty feet apart. I mention 

 these points in regard to drainage, to show that as yet no really well- 

 defined rules have been laid down for the guidance of farmers in deal- 

 ing with it for the improvement of their subjects. It is no doubt very 

 difficult to prescribe any definite style of draining, as a great deal de- 

 pends on the nature of the soil and subsoil ; for a depth and distance 

 apart that will be perfectly effectual in one case, may be utterly useless 

 in another and this may happen within the bounds of a single field. 

 Still it must be acknowledged that, in carrying out this most important 

 work, there is a great deal of hap-hazard practice, even among some who 

 profess to be practical drainers and experienced agricultural engineers. 



Of late years I have had to deal with a large extent of laud which 

 had been previously drained, but on which the drains had ceased to be 

 effective. This I had for the most part redraiued, and while engaged in 

 this work, I found the old drains only about twenty-seven inches deep, and 

 large portions of the pipes choked from mud which had been washed down 

 into them from the soil above, thus proving that drains of that depth are 

 not out of the reach of injury from the surface, especially in a light and 

 porous soil. Shallow drains I consider equally as objectionable as over- 

 deep ones, and my own opinion on the subject is, that parallel drains should 

 in no case be made shallower than three and a half feet, nor, except in some 

 particular cases, deeper than four and a half feet. As to the distance apart, 

 that must in all cases be regulated by the nature of the land to be operated 

 on. Land having a stiff clayey subsoil cannot be made thoroughly dry 

 for profitable farming with drains put in at distances greater than from 

 eighteen to twenty feet. On moderately stiff land the distance may safely 

 be extended to twenty-four feet, while on land having a porous bottom 

 they may be twenty-six or even twenty-eiglrt feet apart; and where the 

 subsoil is found very open and porous, the land may be perfectly well dried 

 by drains at from thirty to thirty-three feet, but beyond the latter distance 

 it is not advisable to lay drains with any hope of success. Seeing, there- 



