504 



STATE BOARD OF AGRICULTURE. 



Fig. 25. Illustrating screen of woven wire to protect outlet of tile. 



It would be well in building the cement work to set in bolts to hold 

 the screen in place as shown in Fig. 25A. 



JOINING LATERALS TO MAINS. 



Mention has already been made of the angle at which the lateral should 

 be brought to the main. 



Two general methods of making connection are suggested. 



1. By the first method the lateral discharges into the side of the 

 main. 



In this case the center of the lateral should come even with the center 

 of the main. This means that if the lateral tile has a smaller diameter 

 than the main tile, the bottom of the lateral ditch must be planned 

 to approach the main ditch higher than the bottom of the main ditch by 

 one-half the difference of the diameters of the main and lateral tiles. 



To make connection, a hole should be picked in the wall of the main 

 at the proper point, and this hole should be made as large as the outside 

 diameter of the lateral tile. The end of the lateral tile should be round- 

 ed back at the sides so that the end when the tile is in place shall stand 

 in flush with the inner wall of the main. When the lateral thus fitted 

 is put into place fragments of broken tile should be carefully laid in 

 over the joint, and earth packed in about it. 



2. By the second method the lateral discharges its water down through 

 the top of the main tile. 



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 suflSciently above 

 the bottom of the main ditch so that the center of the lateral tile shall 

 stand even with the top of the main tile. The end of the lateral tile 

 should project well over the main and should be plugged with a stone 

 or with cement. The same precautions should be taken as in 1 above 



