Bui. 852, U. S. Dept. of Agriculture. 



Plate IV. 



Fig. I. — Deer Flat Forest Pipe Line, Boise Project, U. S. Reclamation 

 Service, Idaho. (Pipe No. 29.) 



Note reinforcement and forms for collar joints. Intake at end of trench in distance. Inset shows 



pipe unit over trench. 





/ 



'"-''.: 





*'-~ty\€ 



Fig. 2. — Churn Creek Siphon, Anderson-Cottonwood Irrigation District, 

 California. (Pipe No. 33b.) 



Longitudinal ridges on interior surface similar to those shown on exterior; due to cracks between 

 form boards. Inset shows inside forms set for monolithic pouring. 



