APPENDIX. 501 



This keeps the earth from falling in, and the running of the water keeps the 

 channel open; the straw not being exposed to the air, remains a long time with- 

 out decaying. This is a common mode of draining in Norfolk, Suffolk, and 

 Essex. 



The best materials for large main drains, where they can be procured, are 

 flat stones which readily split, and of which a square or triangular channel is 

 formed in the bottom of the drain. If the drain is made merely as a trunk to 

 carry off the water, it is best to fill it up with earth, well pressed in, over the 

 channel made by the stones; but if it serves for receiving the water through 

 the sides or from the top, fragments of^tone should be thrown over it to a cer- 

 tain height, and the earth put over these. A very useful draining tile is used 

 in Berkshire and other places, which requires no flat tile under it, even in 

 loose soils, because it has a flat foot to rest on, formed of the two thick edges 

 of the tile, which, nearly meeting when the tile is bent round, form the foot. 

 The section of the tile is like a horse-shoe. It is well adapted for drains where 

 the water springs upwards, and it is less apt to slip out of its place than the 

 common tile. They are usually made twelve or thirteen inches in length, but 

 they are more expensive than the common tiles. 



In draining fields it is usual to make the outlets of the drains in the ditch 

 which bounds them. The fewer outlets there are, the less chance there is of 

 their being choked: they should fall into the ditch at 2 ft. from the bottom, and 

 a wooden trunk, or one of stone, should be laid so that the water may be dis- 

 charged without carrying the soil from the side of the ditch. If there is water 

 in the ditch, it should be kept below the mouth of the drain. The outlets of all 

 drains should be repeatedly examined, to keep them clear; for wherever wain- 

 remains in a drain, it will soon derange or choke it. The drains should be so 

 arranged or turned, that the outlet shall meet the ditch at an obtuse nn^lr 

 towards the lower part where the water runs to. A drain brought at right 

 angles into a ditch must necessarily soon be choked by the deposition of sand 

 and earth at its mouth. 



As the draining of wet clay soils is the only means by which they can be 

 rendered profitable as arable land, and the expense is great, various instru- 

 ments and ploughs have been contrived to diminish manual labour and expe- 

 dite the work. Of these one of the simplest is the common mole-plough, which 

 in very stirl'clay makes a small hollow drain, from 1 ft. to 18 in. below the MII- 

 face, by forcing a pointed iron cylinder horizontally through the ground. It 

 makes a cut through the clay, and leaves a cylindrical channel, through which 

 the water which enters by the slit is carried off. It requires great power to draw 

 it, and can only be used when the clay is moist. In meadows it is extremely 

 useful, and there it need not go more than a foot under the sod. Five to ten 

 acres of grass land may easily be drained by it in a day. It is very apt, how- 

 ever, to be filled in dry weather by the soil falling in; and the animals from 

 which it derives its name often do much damage to it by using it in their sub- 

 terraneous workings. 



But a draining plough has been invented, which, assisted by numerous la- 

 bourers, greatly accelerates the operation of forming drains, by cutting them 

 out in a regular manner, when they are immediately finished with the usual 

 tools and filled up. It has done wonders in some of the wet stiff soils in Sussex, 

 and is much to be recommended in all wet and heavy clays. In stony land it 

 cannot well be used. The subsoil plough, introduced to public notice by Mr. 

 SMITH, of Deanston, may be considered in some measure as a draining plough, 

 for it loosens the subsoil, so that a few main drains are sufficient to carry off 

 all the superfluous moisture; and it has besides the effect of not carrying off 

 more than what is superfluous. By means of judicious drains and the use of 

 the subsoil plough, the stiffest and wettest land may in time become the most 

 fertile. 



The tools used in draining are few and simple. Spades, with tapering blades 

 of different sizes, are required to dig the drains of the proper width, and the 

 sides at a proper angle. Hollow spades are used in very stiff clay. When the 

 drain begins to be very narrow near the bottom, scoops are used, of different 

 sizes, which are fixed to handles at various angles, more conveniently to clear 

 the bottom and lay it smooth to the exact width of the tiles, if these are used; 



