118 SOLE-TILE. 



that of increased friction and loss of velocity. This 

 is a more serious matter than might be supposed, 

 especially in a main drain ; for if several branches 

 deliver into it, and the main has more velocity than 

 the branches, it is evident that, in that proportion, 

 can a smaller pipe be used to convey the same 

 amount of water. In consequence, we lessen the 

 cost of the material, as well as increase the effi- 

 ciency of the work. 



The sole-tile is the best. If laid on strips of 

 board it is more efficient, and in 

 the hands of a skilful workman 

 becomes an excellent drain. A 

 square of turf, strips of waste tin, or, what is better 

 than either, tarred paper, should be placed over the 

 joints to keep out the sand. Many have supposed 

 that the water entered mostly through the substance 

 of the tile. Although this is true to some extent, 

 yet the principal quantity runs in at the joints, and 

 therefore it is necessary that they should be defended 

 from the loose sand which often accompanies it. 

 Vie suffix a table from the " Farm Drainage." 



TABLE H. — Showing the Cost of Soi.e-Tile op diffeuent Sizes. 



