THE DEAINAGE OF GEAS8 LAND. 18 



lie so high, or at such a steep inclination, that the water is dis- 

 charged with sufficient rapidity without artificial aid. Indeed, 

 draining may always be considered unnecessary where the best 

 natural grasses grow luxuriantly. With these exceptions all clay 

 lands, whether the clay is only in the subsoil or rises to the 

 surface, and all peat lands, whether the peat has clay beneath it 

 or not, and in fact all land which is habitually saturated with 

 water, must be efiectuaUy drained before a pasture worth having 

 can be established. 



The prejudice which occasionally exists against the adoption 

 of a system of drainage can generally be traced to some instance 

 where the workmanship has been bad, or where no care has 

 afterwards been taken to maintain the efficiency of the pipes. 

 These ought not to be covered in until they have been proved 

 to work satisfactorily, and as draining is usually put out to 

 contract, this matter needs close personal attention. 



It is a safe general rule not to make any single drain too 

 long, and plenty of fall should be given, or the pipes may not 

 work well after they have been laid some time. A good fall 

 renders them to a considerable extent self-cleansing, and the 

 small drains should not enter the large drains at right angles, but 

 always obliquely, so that the water may retain the momentum 

 received in its previous career. Then the occasional flushing 

 after a sharp storm will prevent the pipes from becoming choked. 

 For short distances near hedgerows or trees, the use of socket 

 pipes securely jointed with cement — not clay — is to be strongly 

 recommended. The slight additional expense may save a large 

 subsequent outlay. 



As to the "depth at which the pipes should be inserted, and 

 the distance between the rows, no definite rule can be laid down. 

 Experience has proved that in heavy land they must be near 

 together, and not too deep ; but in hghter land the Hues may be 

 comparatively far apart. About three feet deep with the rows 

 fifteen feet apart is the usual proportion, but almost every field 

 has some peculiarity of conformation or subsoil which aflects the 



