154 DOMESTIC WATER SUPPLIES FOR THE FARM 



of the spring to prevent the entrance of sand or of matter that has 

 sunk to the bottom, and low enough so the water level will not 

 sink below it in times of drought, nor the strainer, with which it 

 should always be provided, become clogged with matter floating 

 on the surface. 



The water may be carried to the house or barn by direct 

 gravity service or by a siphon such as is described in the preceding 

 section. The cost of pipe will be as there indicated, and the depth 

 of burial about the same. 



Gravity Supplies from Reservoirs. Reservoirs may be 

 either natural or artificial. If the latter, dams for impounding 

 the water will have to be constructed. On the farm these will 

 generally be of earth, with stone or cement flumes supplied with 

 wooden flash boards. Masonry or cement dams are occasionally 

 desirable for damming streams in narrow ravines with rock sides. 



Earth dams should be built of clayey or loamy materials, 

 should not be less than 8 or 10 feet wide at the top, and should 

 have slopes not steeper than 35 or 40, except when faced with 

 stone. It is always best to strip the turf from the ground on which 

 the drain is to rest and to dig a trench 3 feet or more in width, and 

 2 to 3 feet in depth along the center line. This should afterwards 

 be filled with the material of which the dam is built or, better, 

 with puddled clay, a core of which may be carried to advantage 

 up through the center of the dam to the surface. It is always 

 desirable to rest the dam on rock or firm materials, but, if this is 

 not feasible, a low dam may often be made water-tight at the 

 bottom by driving a center piling of slabs or boards. 



The flume may be of wood, of stone set in cement, or entirely 

 of cement. If the latter, the cement should be laid in temporary 

 wooden frames or molds which should be removed as soon as 

 the cement has set. A piling of boards or planks should be set 

 beneath and for several feet each side of the flume, for these are 

 common points of leakage and may, if not attended to, lead to 

 the washing out of the flume or dam. 



Much trouble in home-made dams is often caused by musk- 



