PUMPING MACHINERY 265 



inches from one side of the pit wall, as this will permit 

 the use of pipe tools to better advantage. 



Drilled wells are much like tubular wells except that 

 they are larger, usually 6 or 8 inches in diameter, cased 

 with wrought-iron pipe or galvanized-iron tubing. The 

 pump is independent of the casing and may be removed 

 without molesting it in any way. 



Pump cylinders or barrels usually form a section of 

 the casing in driven and tubular wells. The lower check 

 valve is seated below the barrel by expanding a rubber 

 bush against the walls of the well casing in such a way 

 as to hold it firmly in place. It is to be noted that wooden 

 pump rods should be used for deep-driven and tubular 

 wells, for wooden rods may not only be lighter, but 

 displace a large amount of water, reducing the weight on 

 the pump rod during the up stroke. 



374. Wooden pumps. The first pumps were made of 

 wood, simply bored out smoothly and fitted with a piston. 

 The wood used was either oak, maple, or poplar. Later 

 an iron cylinder was provided for the piston to work in. 

 The better pumps of to-day belonging to this class have 

 porcelain-lined or brass cylinders. These lined cylinders 

 are smoother and are not acted upon by rust. Wooden 

 pumps are nearly all lift pumps and can be used only in 

 shallow wells. The cylinder is fitted in the lower end of 

 the stock and no provision is made for lowering it. 

 Wooden pumps are used with wooden piping, the ends of 

 the pipe being driven into the lower end of the stock so 

 as to form an air-tight joint. 



375. Lift pumps. Lift pumps include all pumps not 

 made to elevate water above the pump standard. For 

 this reason the top of the pump is made open and the 

 pump rod not packed, as is the case in force pumps. Lift 

 pumps, in the cheaper types, are cast in one piece, the 



