No. 4.] HINTS ON LAND DRAINAGE. 375 



will also improve its general chemical and physical qualities ; 

 while the excessive porosity of sandy soils may be improved 

 by the application of clay or marl and decomposed muck or 

 peat, the tine particles of which, tilling the coarser pores of 

 the sand, tend to retard evaporation and to promote the ab- 

 sorption of water from below. 



How to drain Land. 



Under-drainage works can, and if rightly done will, be, 

 strictly speaking, permanent improvements. The construc- 

 tion of farm buildings, roads, walls and fences, though usu- 

 ally classed as such, are of a transitory and ephemeral 

 character, compared with a well planned and thoroughly 

 executed system of tile drainage. 



That a drain may be permanent in its life and action, it 

 must be so planned and constructed as to let the water in 

 and keep the silt or earthy matter out. An open ditch rnay 

 do the first admirably for a time, but soon fills up with the 

 undermining and caving-in of its banks, and by the in- wash- 

 ing of loam and organic matter by the flow of surface waters 

 into it. A stone or ' ' blind " drain may admit water freely 

 for a time, and conducts it fairly well where a considerable 

 inclination or fall to a suitable outlet is practicable ; but 

 when laid (as such drains usually must be) in earth made 

 up of fine particles it is liable to become clogged by the 

 infiltration of silt. 



Such drains can be made silt-proof, and consequently per- 

 manent, by enclosing or surrounding them with silt-exclud- 

 ing materials, such as boards (for a foundation), green 

 brush, turf, old hay or straw, coarse gravel, etc., according 

 to availability and other circumstances, which will readily 

 suggest to the user the best of such means at his disposal. 



Practically, however, where the main object is thorough 

 drainage, and not the clearing up of stone or brush (and in 

 most cases, even where such clearing is collaterally or con- 

 tingently desirable) , tile drains are superior to any other 

 kind, because : — 



They cost less in the sum total of labor and material. 



They admit of being laid at flatter grades, and therefore 



