DRAINAGE. 109 



and If collars are used, there need be no fear of the tile being 

 displaced by the pressure. An idea of the drying capacity of a i|- 

 inch tile may be gained from observing its wetting capacity, by 

 connecting a pipe of this size with a sufficient body of water, 

 at its surface and discharging, over a level dry field, all the water 

 that it will carry. A il-inch pipe will remove all the water 

 that would fall on an acre of land in a very heavy rain, in 24 

 hours — much less time than the water would occupy in getting to 

 the drain in any soil which required draining ; and tiles of this 

 size are ample for the draining of 2 acres. In like manner, 2.\- 

 inch tile will suffice for 8 acres, and 3^-inch tile for 20 acres. 

 The foregoing estimates are, of course, made on the supposition 

 that only the water which falls on the land, (storm water,) is to 

 be removed. For main drains, when greater capacity is required, 

 two tiles may be laid, (side by. side,) or, in such cases, the larger 

 sizes of sole tile may be used, being somewhat cheaper. Where 

 the drains are laid 40 feet apart, about 1,000 tiles per acre will be re- 

 quired, and, in estimating the quantity of tile of the different sizes 

 to be purchased, reference should be had to the foregoing figures : 

 the first 2,000 feet of drain or less requires a collecting drain of i|^- 

 inch tile ; the water from more than 2,000 and less than 7,000 feet 

 may discharge into 2|^-inch tile ; and for the outlet of from 7,000 

 to 20,000 feet, 3^-inch tile may be used. Collars, being more sub- 

 ject to breakage, should be ordered in somewhat larger quantities. 



Laying Tile. — There is a tool made for laying Fig. 40. 



pipes and collars, but it is recommended that they 

 be carefully laid by hand, a process which, though 

 somewhat difficult in narrow ditches, is not impos- 

 sible, and is much more satisfactory. The tiles, 

 each having a collar passed over the end, should be 

 placed along the side of the ditch, within easy reach 

 of a man standing in the bottom. He commences 

 *at the upper end of the ditch, and walks back- pi.k ^^ Ji!^„i„g 

 ward as the work proceeds. The first tile is laid P"fc^-""g "le. 

 with the collar on its lower end, and with a flat stone or bit 

 of broken tile fitted closely against the upper end. The collar 



