24 



BULLETIN 51, U. S. DEPAETMENT OF AGEICULTUEE. 



Water weighs 62.5 pounds per cubic foot and there are 7.48 gallons 

 in a cubic foot. Divide the number of gallons pumped per minute 

 by 7.48 to get the cubic feet pumped per minute. Multiply the 

 cubic feet by 62.5 pounds to get the weight of water pumped per 

 minute. Multiply the weight by the total lift, which will give the 

 foot-pounds of work per minute; 33,000 foot-pounds per minute 

 equal 1 horsepower. Divide the foot-pounds per minute by 33,000 

 and the result will be horsepower. The horsepower as computed 

 from the quantity pumped per minute and the 

 total lift should be doubled, as a pumping outfit 

 usually has an efficiency of about 50 per cent. 

 In general, from 1 to 3 horsepower is all that 

 is required for ordinary farm pumping. In 

 cases where water for the house only is wanted, 

 J to I of a horsepower is sufficient. 



TYPES OF PUMPS. 



There are several types of pumps which may 

 be used in farm pumping. The most common 

 are the ordinary lift pumps which simply 

 raise the water to the ground surface from a 

 shallow well. For elevated tank systems and 

 pneumatic tank systems the combination lift 

 and force pump is necessary. If a special air 

 pump or compressor is not employed it is 

 necessary that a combination air and water 

 pumj) be used for pneumatic tanks, especially 

 in pumping from deep wells. 



There are many types of hand force pumps 

 for shallow and deep well pumping which may 

 be applied to either elevated tank or pneumatic 

 tank systems. 



Figure 15, page IS, shows a deep-well wind- 

 FiG. 20.— Pumping jack for either mill puuipiug Outfit applied to a pucumatic 

 deep or shaUow^vell pumping. ^^^^^ gysteui, and figurc 13, page 16, shows a 



shallow weU windmiU pumping outfit supplymg water to a tank on 

 the windmill tower. Figure 20 is a pumpmg jack which may be 

 comiected with a deep or shallow well pumpmg outfit applied to 

 either system. This jack may be operated by gas engine or electric 

 motor. Figure 21 shows two other types of windmill force pumps, 

 A for shallow wells, and B for deep weDs. 



In obtaining information from the manufacturers of pumping 

 equipment as to the particular equipment which will suit certain 

 needs, the i)ower required, etc., it is well to send data on the follow- 

 mg: The source of water supply, whether a well, spring, or surface 



