CONSTRUCTION 149 



main. In this case an opening is made through the top 

 of the main and through the bottom of the lateral. In 

 digging the lateral ditch, the bottom should stand suffi- 

 ciently high above that of the main ditch, so that the 

 center of the lateral tile shall stand even with the top of 

 the inside diameter of the main tile. The end of the 

 lateral tile should project over the main and should be 

 plugged to prevent the entrance of soil material. (See 



FIG. 61. Shows the connection when the 3-inch tile is fitted in place. 

 It will be observed that the connection is a 90-degree connection. 



Fig. 62.) The same precautions should be taken as indi- 

 cated above to close the joint sufficiently to prevent the 

 soil from working through. 



199. Angles. Some manufacturers of glazed tile 

 are now manufacturing, also, angles and T's in various 

 sizes for making connections between drains. When 

 these can be secured they are desirable, since they reduce 

 labor and insure good connections. In most cases these 

 would be side connections. (See Fig. 63.) The differ- 

 ence in elevation of bottom of main and that of the con- 



