Drainage. 



68 1 



One great object of draining being to prepare the way for deep 

 cultivation by steam or otherv/ise, and as subsoiling may pene- 

 trate to a depth of at least 2 feet, a drain of 2 feet 6 inches in depth 

 should be the minimum on arable land. But no one of large practical 

 experience will attempt to lay down hard and fast rules applicable to 

 all soils, either as regards depth of drain or distances apart. Local 

 experience alone can decide these points. In the stiff clays of the 

 Weald, drains 3 feet deep and 18 feet apart have been productive of 

 the most satisfactory results, while good authorities maintain that 

 upon many of the heavy Norfolk lands, 2\ feet deep and 22 feet apart 

 answer best. The main reason why deep drainage of clay lands has 

 often proved unsuccessful is, that as the depth of drain was increased, 

 the intervals between them were proportionally widened, for no other 

 apparent reason than that of equalizing the cost price per acre ! 



The following table, which approximates to the principles of 

 drainage recommended by the General Board of Health, will give the 

 reader a better idea of the range of prices upon various soils than the 

 most lengthy description. The cost of pipes or draining tiles is 

 reckoned at 30s. per thousand. 



COST OF DRAINAGE PER ACRE. 



At the present day there exists but little difference of opinion as 

 to the best form of drain for arable and pasture lands, for the pipe 

 drain has superseded every other mode. Stone drains of all sizes and 

 of almost every conceivable form have been extensively tried where 

 the material has been abundant ; but none of them approach the 

 perfection of a well-laid round or oval pipe drain. These, when 

 sufficiently protected at the outlets, are almost indestructible. 



For feeders the 2-inch pipe is almost universal ; but the capacity 

 of the mains must depend upon the nature of the soil, as the 

 more porous this is the quicker will the pipe be filled ; while the 

 more rapid the fall, the smaller the pipe required, as it will the more 



