110 FARM APPLIANCES. 



covered with lime or cement mortar, leaving a smooth 

 surface all around the first floor. This should then be 

 covered with a second floor, raised eight or ten inches on 

 a frame of two by ten joists, made of cedar or chestnut. 



Fig. 137. FROST-PROOF CISTERN. 



The earth should be packed closely against this frame, 

 and the top floor should extend a few inches beyond the 

 frame all around. The cistern is then frost and vermin 

 proof. Another important point is to get rid of the sed- 

 iment that gathers at the bottom of every cistern. This 

 is done by carrying the overflow pipe to the bottom of 

 the cistern on a line with the inlet pipe, and thus form- 

 ing a current which disturbs the sediment and carries it 

 into the overflow. This is shown in figure 137, also the 

 arrangement of the draw-pipe, which should have a fine 

 wire strainer on the end, and should rest upon a support 

 near the bottom of a fine strainer, at least two feet high. 

 A piece of one-quarter inch mesh of galvanized wire 

 gauze, bent into a pipe a foot in diameter, and covered 



