484 AGRICULTURAL ENGINEERING 



waste to still lower levels, and if the flow is ample a hydraulic 

 ram or pumping plant can be used. 



Brooks or running streams form another source of water 

 supply, but should be carefully considered before using. A 

 close inspection should be made to determine whether or not 

 the stream is in any danger of pollution by surface washing 

 from manured fields or house and farm yards. River water 

 is quite likely to be turbid during the flood season. Streams 

 flowing through uninhabited or uncultivated upland will fur- 

 nish water of the most desirable character. 



Lakes usually furnish water that is clear and potable, ow- 

 ing to the fact that the water is purified by coming to rest and 

 allowing the impurities to settle. Often, in settled commu- 

 nities, where the practice is not forbidden by law, the banks 

 of lakes are used as a dumping ground for all sorts of 

 refuse. Such practice prevents the use of the water for 

 human consumption. 



Drinking water obtained from a stream or lake should be 

 filtered. A box filled with sand and gravel or charcoal 

 through which the water must pass is the most common type 

 of filter in use. 



The Quantity Required. Care must be taken, in selecting 

 a water supply, to determine that the quantity of water 

 available will be sufficient not only for all present needs but 

 also for any increased demand that may be foreseen. The 

 daily requirements must also be taken into account when 

 planning a reservoir or storage tank. 



The greater part of the water consumed on the farm is 

 required by the live stock for drinking purposes and by the 

 household. The house requirements depend largely on 

 whether or not plumbing fixtures are installed. The amount 

 consumed per day by each of the various farm animals is 

 about as follows: A horse, 7 gallons; a cow, 6 gallons; a 



