118 



COALFIELDS AND COLLIERIES OF AUSTRALIA. 



To drain the dip workings, an Evans' hydraulic pumping: 

 engine is used; while to raise the water to the surface, a Blake 

 steam pump is located near the bottom of the main shaft. The 

 construction of the hydraulic pumping engine can be seen by 

 referring to Fig. 58. The motor cylinder (A) has two valves 

 (B and 0) above it; the piston rod (R) is a continuation of the 

 rod of the plunger. The water for motive purposes first enters 

 the chest of the auxiliary valve (B), from which it passes 

 through a port into the chest of the valve (C). There is also 

 a communication with the main valve chamber (J;, from which 

 the water passes into the cylinder (A), through the ports (b) 

 and (c). The exhaust water flo\vs into the sump through the 

 port (d). The auxiliary valve is operated mechanically by the 

 arm (L), attached to the piston rod, which,, while moving 



Fig. 58. Evnns' Hydraulic Pumping Engine. 



alternately backwards and forwards, strikes in turn the lugs 

 (M.M.) attached to the rod (N) that actuates the rocker (0), 

 connected with the far end of which is the link (Q), attached 

 to the valve stem (S). A small quantity of water under pres- 

 sure due to head is thus enabled to lift a! larger quantity of 

 water a lesser height. The motive -water presses equally on 

 either side of the valve (B), which, being moved mechanically 

 first on one side and then on the other, allows the water to 

 pass alternately down the ports (a and e) to the valve chest 

 (C), and from the latter to the water exhaust pipe. The area 



