186 THE BOOK OF THE LANDED ESTATE. 



given depth can be set down. To make them deep enough to dry the 

 surface thoroughly might require a greater depth than would be judi- 

 cious for the safety of the sheep, and more especially of lambs. From 

 fifteen to eighteen inches is a very fair medium depth for the ordinary 

 soils of hill -land, and for the safety of sheep; and besides, by giving 

 them a good width at top, and keeping them narrow at the bottom, they 

 thus have a great slope on the, sides, which is an advantage. The soil 

 in all cases of main drains should be spread out on each side, to prevent 

 it being trodden in again by sheep. The main drains ef and g h may 

 in many instances be sufficient to carry away the water from the hill 

 either into a stream at the foot or into closed drains in fields below; but 

 in many cases it may be necessary to make other main drains, through 

 natural hollows in the hill, as the case may be, as shown at a b, b c, a b, 

 6 d, and a i, in fig. 67. 



The small drains are usually cut according to fig. 68. They are cut 



Fio. 88. 



about twenty-foxir inches wide at top, from a to 6 on the sketch, making 

 a good slope from a to b, and eighteen inches deep, measiiring by the 

 slope, and from twelve to fourteen inches deep on the low side, as at & d, 

 the bottom being about nine inches wide. All the soil taken from the 

 drain is put upon the low side, as shown at e, but not heaped up too 

 high, as it is apt to be worked back into the drain by the sheep. 



This kind of drain has cost me from 9d. to Is. 3d. per chain of twenty- 

 two yards, according to the hardness of the soil, and the length and 

 strength of heath on the surface. 



SECTION 4. TJie Draining of Woods and Plantations. 



Even after all the benefits which have been derived from the drainage 

 of agricultural lands, and the evident desire there is with many landed 

 proprietors to have their farms thoroughly drained, it is surprising that 



