DIFFERENT FORMS OF DRAIN. 



331 



ANOTHER FORM OF CONDUIT. 



and far more perfectly than drains composed merely of 

 a mass of loose stones or rubbish. 



Draining-tiles, when of the best form, are one-fourth 

 higher than they are wide, 

 the sides nearly perpendi- 

 cular, and the top rather 

 abruptly turned. Such as 

 spread out at the sides and 

 are flat at the top, prove 

 weak and bad for conveying 

 water. Such as are without 

 soles or flat tiles at the bot- 

 tom are liable to sink and 

 get out of place. Some 

 drainers, indeed, think soles 

 unnecessary in hard-bot- 

 tomed land : but it is scarcely 

 to be doubted that the quan- 

 tity of water constantly sink- 

 ing to the bottom of the di-ain nmst gradually soften 

 the stiffest clay, and cause the tiles to sink and become 

 less effectual. This the soles would entirely prevent. 

 A great objection to soles 

 has been their cost ; but in 

 places where slate is to be 

 cheaply obtained, this may DRAINING-TILES WITH SOLES. 

 be used as a substitute. 



The breadth of the sole determines the width of the 

 bottom of the drain. Sometimes it is made ten inches 

 wide, the tile being four or five inches inside measure : 

 where the tile is smaller, the sole is also narrower in 

 proportion, except in main-drains, where it is always of 

 one width. The sole therefore always exceeds the width 

 of the tile, and it is better that it should be wide than 

 narrow in proportion, the space on each side being filled 

 in with earth, or with stones and clay. The length of 

 the draining-tile is from twelve to fifteen inches, the 

 latter being in some respects the best, giving less trouble 



