METHODS OF RAISING WATER 



125 



is placed below the water level, but is frequently just above it 



(Fig. 54). In very deep wells the pump cylinders are placed below 



water at the maximum depth to 



which it is lowered by pumping and 



are heavy and strongly constructed 



to withstand the considerable strain 



placed upon them. Ordinary forms 



of deep well or lift pumps cost from 



$3 to #4 when operated by hand, 



and from $3.50 to #5.00 when fitted 



for operation by windmills. 



Force Pumps. -- Force pumps 

 not only raise the water from the 

 well, but lift it to tanks or other 

 containers, often at considerable 

 heights above the pump. There 

 are many forms of force pumps, 

 but they are all modifications either 

 of the common suction or of the 

 deep well pump. The chief differ- 

 ence from the shallow well pumps 

 lies in the use of pipes running to 

 elevated tanks in place of open 

 spouts. This necessitates either a 

 solid plunger or a stuffing box at 

 the top of the pump cylinder to prevent the escape of water, and 

 in most cases an air chamber is attached to equalize the pressure, 

 prevent strains and to give a continuous discharge. Simple forms 

 of force pumps (often without air chamber) may be had from 

 #5 to #6, if to be operated by hand, or from #6.50 to #10, if to 

 be operated by windmills. 



Two of the most common forms of force pumps are shown in 

 Figs. 55 and 56. 



In the common house force pump, where the lift is very slight, 

 the air chamber is often omitted, and a valve provided to allow 

 the water to escape or force it to a tank as desired. 



'TUBULAR' 



INDEPENDENT 

 PUMP 



FIG. 54. Common arrangements of 

 deep well pumps. 



