214 COALFIELDS AND COLLIERIES OF AUSTRALIA. 



as far as it will go towards the back end of the s'teelyard, 

 the machine is not properly adjusted, turn it back, as far as 

 it will go in the opposite direction, take out the plug 

 in counterpoise (C), and drop small shot into the cup until it 

 is just heavy enough to bring down the point of the steelyard. 

 So as to preserve the machine from wear, the platform should 

 be solid upon the frame and the centres be detached from their 

 bearings when not in use. This is done by manipulating a 

 lever. Pooley's pit-bank weighing machine is made in many 



Fig. 137. Patent Self-indicating Pit-bank weighing machine 



different styles, that generally in use indicating the weights 

 automatically, so that the weighman and check weighman can 

 readily read the figures (Fig. 137). The later machines go 

 further, and register the nett weight on a travelling band. 

 The platforms are sometimes provided with a turn table for 

 facilitating the disposal of the skip. In these machines all 

 the sustaining points are suspended, not rigid ; the knife-edges 

 are all in parallel planes, and the levers all oscillate in one 

 direction, so there is a minimum chance of injury due to jar. 





