On the Drainage of Land. 



167 



The best materials for such drains are gorse and white-thorn.* The 

 common hawthorn, willow tops, and other materials, are also used. 

 The thorns ought not to be cut till the leaf is fallen, else the dead leaves 

 will encumber the drain. 



Sod-draining requires a more explicit description ; for, though not 

 unknown elsewhere, it is not, I believe, very generally practised. One 

 mode of sod-draining is by digging a drain about a foot wide, and then 

 doubling the sod into the shape of an inverted V, with the grass inwards. 

 The sods are then laid in the drain, resting on their edges, with the bent 

 middle upwards. I have known drains of this kind to last very many 

 years. 



The more common and more effectual way of sod-draining is, how- 

 ever, as follows. The turf along the intended line of drain is cut with 

 a turfing spade into a quadrangular shape c h b' c' (fig. 1), 9 inches 



c a a t 



O 



c c' = 9 inches. 

 a a^ = 3 inches. 

 h b' = Q inches. 



a m — \ foot. 

 e c" = 18 inches. 

 € a" = Q inches. 



Earth 



So/ds 



Drain 



Section of a sod-drain. 



Longitudinal view of a sod- drain. 



wide at top and 6 inches wide at bottom. Narrow wedges, acb^a' c' b', 

 are next cut off on each side, and thrown aside, leaving the sod about 

 3 inches wide on the grass side and 6 inches wide underneath. The 

 sods are then raised with a spade, each sod being about a foot long and 

 6 inches deep. The ends a b (fig. 2), &c. slanting off, so that each sod 

 overlaps its neighbour. 



The sod having been thus removed, a "spit " of earth is taken out, 

 and the crumbs are removed with a common draining- scoop. Another 

 spit is then taken out with a narrow spade, and the loose earth is again 

 removed with a narrow scoop, such as is used in making thorn-drains. 

 The drain thus formed is wedge-shaped (see fig. 3), being about 18 

 inches deep, about 9 inches wide at top, and scarcely an inch wide at 

 bottom. The depth and width of course vary a little, if the level of the 

 surface requires it. In this respect sod-drains have an advantage over 

 mole-drains, which must be parallel to the level of the surface. They 

 may therefore be carried over ridges and other inequalities where the 

 mole-plough would be unavailable. 



The sod is next placed in the drain with the grass-side downwards, 



Alder is very durable ; heath and black -thorn probably the most durable of all. 



