WELLS, PUMPS, CISTERNS, FILTERS. Ill 



with thick flannel cloth, doubled, makes a filter for the 

 water. 



WATER IN THE BARN YARD. 



Water in the barn yard is a great economy and con- 

 venience ; by a little management it can be secured with 

 ease. The difficulties in the way, are chiefly in bringing 

 the water down hill, over an elevation midway, and 



Fig. 138. CONVEYING WATER BY SIPHON. 



in bringing it up hill, from a spring or well below the 

 level. In the former case, a siphon must be used, as 

 shown in figure 138. It consists of a pipe, one end of 

 which is under the surface of the water in a well or 

 spring, and carried over a ridge, and down a slope, to a 

 lower level. This method is open to one objection, 

 which nearly always gives trouble. There is more or 

 less air dissolved in water; this dissolved air escapes, 

 as the water is flowing through the pipe, and gathers at 

 the highest point, where it stops the flow. To remove 

 this air, the following arrangement is made. A short 

 pipe, furnished with a stop cock and a funnel, is fitted 

 to the highest point of the siphon. When the flow 

 begins to be obstructed by air, the stop cock at the lower 

 end of the pipe is shut, and that at the top is opened. 



