CHAPTER XIII. 



FARM WELLS. 



340. Essential Features of a Good Well. The essential 

 features of a good well are : (1) Ample capacity to supply 

 pure, clear, cold water. (2) A location which renders it not 

 likely to be contaminated by seepage from surface impuri- 

 ties. (3) A casing or curbing which is vermin proof at 

 the top and if possible water-proof in its upper 10 to 20 feet. 



341. The Capacity of a Well The capacity of a well 

 should always, if possible, be much greater than the prob- 

 able demands which will be put upon it, and it should not 

 be possible in a few hours to pump it dry with an ordinary 

 pump. 



In working the ordinary domestic pump about 20 strokes 

 are made per minute and these will fill a pail with 20 to 24 

 pounds ; this is at the rate of about a cubic foot or 7.5 gal- 

 lons in 3 minutes and a good well should be able 1o supply 

 water at this rate for several hours without failing. 



The domestic animals on the farm will need water at the 

 rate of more rather than less than a cubic foot per each 

 1,000 Ibs. of weight per day. A cow giving a heavy flow of 

 milk often takes nearly 2 cubic feet of water in 24 hours. 



Five cows, during 120 days in winter, averaged 85.4 Ibs. 

 per head when the water was warm and 77.3 Ibs. when it 

 was cold. At this rate the equivalent of 40 adult cows 

 would need 3,416 Ibs. of water or 54.7 cubic feet and this 

 would require, at the rate assumed above for pumping, 2 

 hours and 45 minutes to supply them, 



