Bench Construction 



these tiles can best be seen by referring to the cut on page 167.) In laying 

 these tiles, they are bound together by cementing the ends as fast as they are 

 laid. 



A layer of Portland cement, three-quarters of an inch in thickness, is 

 flowed over the tile, forming a complete water-tight lining. The material is 

 made by using the best quality of Portland cement. We have preferred the 

 Dyckerhoff Portland cement for this purpose, as we have had better results 

 from it than from other brands thus far tested. Great care must be used in 

 preparing this cement, the proportions being two parts of pure, clean, fine 



A, E Cypress Strips 

 B 6 in. Soil 

 C Water Canals 

 D Porous Tile 

 F Iron Knee 

 G Tee Iron Bearer 

 H y x inch Cement 

 Lining 



I Terra Cotta Tile 

 J Yellow Pine Bearer 

 K Locust Post 

 L Grouting 

 M Ground Line 

 NFlow Pipe 

 O Return Pipe 



Cross Section Sub-Irrigation Bench 



sharp sand to one part of cement. The sand and cement are mixed when 

 dry, and are then moistened by the addition of water until of the proper 

 consistency. While the cement is setting it will be necessary to "trowel 

 it down," as masons call it ; that is, to smooth over the cement several times 

 with the trowel. This is done in order to prevent fine cracks or crevices 

 working into the cement. 



At every twenty feet an expansion joint composed of sheet lead worked 

 into the bench is made. A cement bench will contract and expand with the 



166 



