532 Reading-Course for Farmers. 



going over rocks and inequalities in the ground, this trouble may be 

 avoided to a certain extent by placing at the highest point a T and stand- 

 pipe about one foot high with pit-cock at top. If the pipe becomes air 

 bound, open the cock in stand-pipe and allow the air to escape. As soon 

 as water begins to come, close the cock. The stand-pipe should be pro- 

 tected from freezing by a covering of soil. It may be made more accessi- 

 ble by placing around it a piece of tile reaching nearly to the surface of 

 the ground. If pipe is deep in the ground, a long iron wrench may be 

 used with which to turn the cock. 



In a long underground pipe it is always well to put Ts every three 

 hundred or four hundred feet with short stand-pipe and cock. In case 

 the pipe becomes clogged, you may begin from the upper end and force 

 water up through one section at a time with a force pump and thus open 

 the pipe without having to tear it all up. Dirt collects in largest cpantity 

 at the joints of pipes where the couping does not bring the pipes close 

 together and where the galvanizing is not perfect. Water forced througli 

 the pipe in the opposite direction from the usual flow will often remove 

 the obstruction. 



When pipe is used to siphon water over a point higher than the 

 source of supply, the pipe is likely to become air-bound at the highest 

 point. Here a stand-pipe two feet high, if possible, should be provided. 

 Valves should be placed at both ends of the pipe and a cock at top of 

 stand-pipe. By closing valves at the ends so that the water will not 

 escape, you can open the cock and pour water into the stand-pipe where 

 the air has collected. Never attempt to siphon more than twenty feet 

 liigher than source. 



Pipes in exposed places in buildings may be protected from freezing 

 by wrapping with asbestos paper and then covering with plaster of paris 

 one or two inches thick. This is more economical than a large quantity 

 of asbestos. A wooden trough or form may be made to hold the plaster 

 of paris around the pipes while it is hardening. The cost may be still 

 further reduced without lessening the protection by mixing the plaster of 

 paris with equal quantities of sawdust. 



Reservoirs 



Reservoirs for storage of water may be made by sinking wooden 

 tanks of desired capacity in the soil, leaving about one foot of space 

 around them on all sides. Fill this space with cement and leave to harden. 

 After the cement has set, the wooden tank may be removed or it may be 

 left until it decays. Wooden tanks may be made of clear pine, cedar or 

 cypress. The cypress is cheapest and in most cases will last as long as 

 the others. The average life of a wooden tank is twelve years. The 



