54 



THE PRACTICAL GARDENER. 



is not unfrequently used in countries where none of the above- 

 mentioned materials are to be procured, and although making 

 a less permanent di'ain, will, for a few years, act sufficiently, 

 yet, fi'om the liability of wood to decay, it is probably the 

 worst material that can be chosen for this purpose. Earthen- 

 ware tiles of various forms and sizes, have been used for 

 draining, but these materials are better adapted for carry- 

 ing off the water when once collected, than for the actual pur- 

 pose of collecting it ; however, they are sometimes made per- 

 forated with a considerable number of holes for the purpose 

 of admitting the water into them. For lands liable to sudden 

 inundations, tile-draining is excellent, and the nearer the 

 surface they are, provided they be under the reach of the 

 plough or spade, the more effectually will they act. Which- 

 ever of these materials be used, it is important that they 

 be laid as hollow as possible, that the water may the more 

 readily find a passage through them ; and, in forming the main 

 or principal di'ains, they should be built, so as to leave an open 

 space, at least nine inches or a foot square, at their bottoms ; 

 over this should be laid, in an open manner, a sufficiency of 

 the same material wherewith to fill the drains to within a 

 few inches of the surface of the walks, if the drains be placed 

 under them, and to within fifteen or eighteen inches of the sur- 

 face of the ground, when they are under the quarters or borders. 

 The depth at which these principal drains should run, can only 

 be determined by local circumstances ; but the collecting 

 or cross drains need not be either so deep nor yet so broad, 

 neither is it requisite that they should be built with a va- 

 cuity so capacious. For most purposes, a space of a few 

 inches in the clear will be sufficient, and should be formed 

 of the following shape. A, which is readily done by placing the 

 larger pieces of the materials resting against each other at the 

 top, and thus forming a rude, though strong arch, capable of 

 resisting any pressure, which is likely to be placed upon it. Like 

 the main drains, the nearer to the surface these smaller ones 

 can be filled with porous materials, the better will they collect 

 and carry off the superabundant water. In draining with 

 brush-wood, no cavity is usually formed, although no doubt 

 can exist that for principal drains, two planks laid so as to leave 



