312 University Geological Survey of Kansas. 
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Fig. 83. Common form of working valves for Cornish pump. 
Bogss.—So far we have considered only the pump proper— 
the actuating mechanism and power end will now be con- 
sidered. ‘Transmission of the power from the engine to the 
pump rod is an important consideration, which is accom- 
plished by ‘‘bobs,’’ ‘‘pendulums,’’ or walking beams. 
Two general forms are seen in this district, one the straight 
beam, the other the angle-beam bob. There are, however, a 
host of modifications of each form. The straight-beam bob 
is shown in figure 79, in this case, however, being a double- 
beam bob. One engine is employed in driving both beams 
and through them the two pumps. 
A framework, A, supports the gearing, B, which is driven 
by a pulley on a shaft, C. Two cranks, D and #H, are fastened 
to either end of the shaft supporting the large spur wheel. 
They are connected with the fore ends of the beams, F and G, 
by pitman rods, while the opposite or rear ends of the beams 
