314 University Geological Survey of Kansas. 
are fastened to the pump rods by pivot clamps, in order that 
the pump rods may be lowered or lengthened as the column 
pipes are lengthened. 
The angle bob is shown in figure 1, plate XLIII and figure 
80. The framework, A, supports the beam, C. The timber, 
B, is at right angles to C, and is securely fastened to it and 
braced by the timbers, D. Power is applied to the extremity 
of B by means of a pitman, H, which is connected with a gear- 
ing not shown in the cut, but similar to that shown in figure 79. 
A counter weight, Ff, is mounted upon and fastened to the 
free end of the beam, CU, so as to make the working of the 
pump more smooth and uniform. 
The adoption of either of these forms of bobs is determined 
by the condition met with at the mine in question, but some 
means of transforming the curvilinear (or rotary motion) 
of the engine or gear into a rectilinear (or straight line mo- 
tion) is absolutely necessary. Furthermore, the transforma- 
tion must result in a vertical rectilinear motion, as the pump 
rod must work up and down vertically. 
It is also necessary, both in order to avoid useless waste of 
power in lifting the main pump rod and to prevent its de- 
scending with too great speed, to counterbalance as much of 
the weight as is not doing useful work. ‘This is readily ac- 
complished by the balanced bob in its different forms. 
STEAM PUMPS. 
Although the first cost and the running expenses of steam 
pumps are greater than that of the Cornish system, yet the 
convenience in handling and the small space occupied by 
these pumps are much in their favor. A serious objection 
to the use of steam in the mine is the escape of the exhaust 
steam, which not only adds moisture to the mine air, but 
also increases the temperature, both of which add to the dis- 
comfort of the men, besides rotting the mine timber, when 
timbering is employed. When the pump is located in the 
shaft, the exhaust steam, as well as the radiation from the 
pipes, may materially facilitate the ventilation, but when lo- 
cated at a distance from the shaft, some form of condenser 
should be employed. As, however, these pumps are rarely 
