522 Reading-Course for Farmers. 



for a pump which costs ten cents a day to run. (2) Another reason for 

 preferring a gravity supply aside from the cost is its greater rcHabiUty. 

 The best machinery may break down even under expert care, and the 

 probabihty is, that there would be many days in the year when, with 

 pumps, the house would be without water on account of accidents. 



Rams. — If a fall of water is available, its power may be used to 

 work a hydraulic ram and this gives as cheap a supply as by gravity, 

 since the occasional care required is very little, and the fall of the water 

 does all the work. The two disadvantages are, — ( i ) that the fall is not 

 always available at the right place, and (2) from accumulation of air in 

 summer and from the formation of ice in the winter, the ram is subject 

 to interruptions. In winter the ram may be kept from freezing by housing 

 it and providing a small coal fire for the coldest weather. The following 

 table gives data as to size, cost, etc., of hydraulic rams : 



This table is based on the assumption that the length of discharge 

 pipe is not over 100 feet and that the head against which the ram works 

 is not over five times as great as the fall of the stream. The drive pipe 

 should be' made always as short as possible. 



Windmills. — Another cheap but unreliable source of power for 

 water pumping is a windmill, which, while of great service in windy 

 weather, is useless at other times. The frequency of winds of sufficient 

 force to turn a mill varies in different localities, but it is probable that 

 in any part of the eastern states five or six days might pass without a 

 wind of any value. Therefore, the tank into which the water is pumped 

 ought to be large enough to hold about a week's supply, or 300 x 7 feet ; 

 or 2,100 gallons besides the water needed for the stock (say 4,000 gallons 

 or 500 cubic feet). This means a tank eight feet cube, or ten feet 

 diameter and six feet deep. Then, since the wind, when it does blow, may 

 not be strong or may last only a short time during which the tank should 

 be filled, the mill and pump ought to be of good size. A twelve-foot mill 

 ought to fill such a tank in about two hours, the pump working at the rate 

 of eighteen gallons per minute. It would be ft)olish indeed to install a 

 windmill, pump and tank only to find that in hot weather, when an 

 abundant supply of water is particularly necessary, no water could be had 

 from lack of wind. 



