RESERVOIR BUILDING. 57 



once, leveling and filling hoofprints so that all tramping 

 or pressure of the scraper in passing may tend toward 

 even packing of the soil. All spots not reached by the 

 team or tools should be tramped by the shoveler so that 

 no loose dirt may be covered. This work should be con- 

 tinued all through the building. The harrow should fol- 

 low the plow in the bottom before the scraper moves the 

 dirt to the bank. 



Sixth : The outflow pipe should be put in early. A 

 wooden box is often used having an interior space of six 

 by six inches, but a four or six inch lap-welded steel or 

 cast-iron pipe is vastly better. It should have an elbow 

 turned up on the inside so that a plug with a long handle 

 can be used to open or close the exit. A valve is better 

 than a plug, but it costs more. The pipe should be bedded 

 in a mass of concrete so that it will not be loosened by 

 working the exit apparatus. 



Seventh: The width of the embankment is governed 

 by its height. The slopes with the best of earth should 

 not be less than two feet horizontal to one foot vertical 

 on the inside; and if the material is light, three to one 

 on the outside will be none too much. 



Eighth : The bottom and inside of the reservoir banks 

 should be well puddled. This is done by thorough plowing 

 and harrowing or cultivating to a depth of eight inches 

 and then admitting water slowly and keep the teams going 

 with the harrow. Begin at the center and work round 

 and round until the mud becomes as smooth as pancake 

 batter, working and reworking away from the center until 

 the puddle is carried well up the sloping bank. This 

 puddle layer, if the soil is fitted for it, will make the 

 pond hold water. 



A Small Reservoir in Sandy Soil. The foregoing con : 

 struction will not hold water if the materials are too coarse 

 in character. Where percolation is free a water-tight cov- 

 ering for the bottom and banks must be provided. This 

 can be done by hauling in clay for a puddle or the reser- 



