ON THE irilPEOVEMENT OF WASTE LAND. 61 



this, and a leading drain 3 feet wide was taken up through 

 the hed of the old dam (now dry rich land) for a mile and a 

 quarter, gradually narrowing towards the head, but from 5 to 6 

 feet deep throughout, so that the sub-leaders have a clear drop 

 into it. The small drains (4 feet) have a similar drop into the 

 sub-leaders, and are carried up so as to terminate in the base of 

 the hills, where the subsoil is very open gravel. By thus rais- 

 ing the heads of the drains a constant scour is secured, and that 

 by the purest water. This open subsoil before the drainage 

 was so full of water, which was kept on dam by the close loam 

 below, that it used to rise to the surface as the only outlet, and 

 sour the whole plain. The advantage of having the heads of the 

 drains carried up as I have described has proved so great that 

 fewer drains effect the same object, and not only is much outlay 

 saved, but the pipes are kept as clean as gun-barrels. Of course, 

 this advantage can only be attained in hilly districts, but in such 

 districts it never should be overlooked. An additional advantage 

 may be attained, as in the case I refer to, by placing field stones 

 over the pipes to within 18 inches of the surface, for about 12 

 feet from the heads of the drains, the throw of water being much 

 increased thereby. 



The leading drain for so considerable an extent of ground 

 must of necessity require a large duct (in this case its capacity 

 at the outfall is nearly 3 feet by 15 inches), and it was found that 

 pipes of the required size Avould be very expensive ; the plan was 

 therefore fallen upon of joining open-ended boxes made of old 

 larch, in the faucet joint form. These boxes are not only 

 fastened with nails, but with wooden pin.«!. The idea of using 

 wood was taken from finding a plank under the foundation of 

 an old bridge perfectly fresh, after being there upwards of 100 

 years. 



The main outfall is upon a flat rock 2 acres in extent, over 

 which the main stream runs, and the spread of the water being so 

 great, the run from the great drain is never stilled even in the 

 heaviest floods. 



At the head, this drain is 2i feet below the level of the bed 

 of the main stream, and by a few large pipes connecting the two, 

 the whole of the water from the stream can in dry weather be 

 turned in to scour out the leading drain. 



This land had been let in very small farms, and most of the 

 tenants had fallen into hopeless difficulty, which obliged the 

 proprietor to take it into his own hands for improvement. The 

 drainage was not quite finished when one of the largest sheep 

 farmers in the country (without the lands being advertised) 

 offered to take the greater part, at a slight increase of the old 

 rent, and to pay 6 J per cent, on the gross outlay, and he now 

 holds them on these terms. 



