ZIG-ZAG COLLIERY. 



117 



wheels of the greaser, the latter revolve slightly with the fric- 

 tion, while the spring, which is fixed at one end,, but free to 

 move at the other, exerts the necessary pressure. The spring 

 is Ijin, by fin., and the greaser wheels are 12iii. in diameter. 

 A pair of wheels are on one axle. The greaser wheels are 

 smooth, and have not semi-circular pieces cut out of their 

 periphery to fit the skip axles, for the latter require very little 

 grease, and as these skips travel faster than they would in the 

 case of an endless rope, the notches, would pick up too much 

 grease, and splash it about. 



Fig. 57. Travelling Tippler. 



In the bords the usual bridge rails are used in lengths of 

 4ft. Gin. and 12ft. These are light, require no fishplates, and 

 are fastened to the sleepers with] plate nails. Horses 15.1 

 hands high draw the skips from the working places to the rope 

 haulage. Naked lights are used, the lamp being the ordinary 

 small coffee-pot type, carried on the front of the cap, against 

 a piece of leather. In these Chinese oil is burnt, which is an 

 oil made from the arachis or peanut. After weighing the 

 skips they are run into a travelling tippler, which is an end 

 tippler mounted on a trolly (Fig. 57), that can be run over a 

 row of hoppers. The track is given a slight downward grade 

 for the full lode, so that the force required to move it about 

 equals that necessary to push the empty up again. 



