236 COALFIELDS AND COLLIERIES OF AUSTRALIA. 



The cutter is conveyed along the headings in a plain drop end 

 truck drawn b.y a horse. 



The pick-quick (Fig. 150) is a bar machine constructed 

 for longwall work, for which purpose it is used in the thin por- 

 tion of the seam at Mt. Hembla. At this colliery the pick- 

 quick machines are direct current, flame-proof, mounted on 

 stands, and can undercut 4ft. Gin. deep, the height of the cut 



Fig. 149 "Goodman" Low-vein Electric Chain Breast 

 Machine. 



being from 4in. to 5^in. The gearing between the motor and 

 the bar is 2 to 1. Owing to the small diameter of the bar, 

 and the fact that it is close to the coal, it is less likely to be 

 jambed by the coal should the latter be tender, than 

 other types of coal cutters ; also props can be set 

 under the coal closer than with, say, a disc machine. 

 The bar is a tapered rod with a spiral thread formed on it ; 



Fig. 150 The Pick-quick Direct-current Cutter on Skids. 



the cutters are arranged in the space between the thread. The 

 cutter picks have tapered shanks, and a feather is formed on 

 one side so as to fit the tapered and seated holes in the cutter 

 bar. For cutting in coal, the cutters are shaped to a point; 

 for cutting in slate, they are dressed to a chisel shape, fin. 

 wide. The cutters must project a uniform distance above the 



