Bui. 852, U. S. Dept. of Agriculture 
Plate I. 
Fig. I. — Excessive Roughness Ob- 
tained with Poorly Made Wood 
Forms. 
Ellipsed outlet to 60-inch round siphon pipe. 
Fig. 2. — Flow Obstructed with 
Accretion of Sand and Gravel, 
Cemented by Carbonate of 
Lime. 
Note "mortar squeeze" at the joints; typical 
of very old lines. View taken after 14 years' 
use. 
Fig. 3. — Pipe Unit for Victoria Aqueduct, British Columbia. 
Exceeding smoothness obtained with oiled steel forms and omission of any wash coat. 
