20 



SCIENCE OF GARDENING. 



come ill the way of the spade. Three feet^ or eveu three 

 feet six inches will be about the right depth, with the 

 main drain six inches lower. The drains should follow 

 the natural fall of the land, and have a tolerably good 

 fall, which can be obtained by cutting them a little deeper 

 at one end w^here there is no slope in the land. They 

 ought to be three inches wide at the bottom, and fourteen 

 or fifteen inches at the top, the main drain (which may 

 discharge itself into the house drain or any other outfall 

 that can be had) being made a little wider. Where tiles 

 or pipes can be procured, those with a flat bottom are the 

 best, otherwise tiles will require a slate sole to rest upon. 

 Pipes of two inches diameter, and three inches for the 

 main drain, will be sufficient. In the absence of tiles or 

 pipes, each drain may be filled to within fifteen inches of 

 the surface with old brick rubbish that is not too small, 

 rough stones, broken earthenware, cinders, strong gravel, 

 or broken rock or rubble in a rocky district. A few 

 branches may then be laid over each, and the same ma- 

 terials should be placed over tile drains to within a like 

 distance of the surface. The drains may be four or five 

 yards o.part, in parallel lines, and the ma,in drain along 

 one boundary. 



Plants in pots require special attention as to draining, 

 for they are in a more artificial state, and are liable to be 

 much injured by superfluous water. In addition to 

 putting plenty of drainage in the bottom of the pots, a 

 few small pieces of broken stone or brick, with lumpy 

 fragments of decayed turf or peat, may be mixed sparingly 

 with the soil, to perfect the drainage. 



2. — Operating on Soil. 



Trenching should always follow draining, or the latter 

 will act but partially. Unless the ground be stirred pretty 

 deeply, half the effect of draining will be lost. Both must 

 be done in the autumn or early part of the winter, and 

 the ground will then be in a good state for cropping in 

 spring. These and all other operations on ground should 

 always be done when it is in a moderately dry state. If 

 it be worked and trampled while wet, especially when it is 



