THE YOUNG FAKMER'S MANUAL. 307 



places will very soon decay, forming a complete bed of mellow, 

 fine earth, which will be very easily washed into the calibre, or 

 worked in by moles or mice. When straw or shavings are used, 

 they soon decay, and furnish an abundance of the right kind of 

 substance to obstruct the water passage. When mellow earth is 

 placed on the stone, moles and mice will haul it down and fill the 

 throat full in one season. But if hard earth is placed directly on 

 the stones, they find it impossible to work holes through it ; and, 

 therefore, they will not be able to obstruct the water passage 

 with earth. I was once accustomed to put straw on the stones 

 in my drains, and to place sods, inverted, next to the stones ; but 

 I found that the moles and meadow mice made holes so readily 

 from the throat to the surface of the ground, and hauled in so 

 much dirt, that I abandoned the use of straw entirely ; and in 

 stead of putting the sods on the stones, the hard subsoil is always 

 placed directly on them. 



424. My practice now is and I find that all our best farmers 

 are adopting it to return not less than six inches in depth of the 

 hardest sub-soil directly on the tile or stone. I always prefer to 

 shovel it in when it is wet, as it will set, and form a more compact 

 covering when it is wet than it will when the dirt will crumble. 

 In covering tile, I always fill with a shovel about six inches above 

 the tile, and exercise great care that small stones do not fall on 

 the tile, and crush them. In covering stone, I shovel in about 

 six inches of hard dirt, and then tread it down firmly not with 

 a horse, as I have read of in some agricultural journals, but 

 with my own feet. After this, plow in the dirt with one horse. 

 One horse is better than two horses, even when they draw by 

 a long whippletree, because they are usually afraid of getting into 

 the ditch. After the ditch has been filled so that one horse can 

 travel on the dirt in it without danger of displacing the stone or 

 tile, it is best to plow with two horses. Great care should be ex 

 ercised by the workmen not to allow a horse to step in a ditch 

 when there is but little earth over the stone or tile, as he will 

 surely displace some of them. 



425. Of the many hundreds of rods of underdrains which are 



