STOCKTON 130KEHOLE COLLIERY. 303 



on account of friction ; the lower part of the ring dips into an 

 oil chamber, so when revolving it brings up some oil. The 

 oil, which finds its way out at the end of the spindle, falls into 

 a recess connected to the body of the plummer block by a 

 port. A tap enables the oil to be drawn off when it becomes 

 too thick. A cap is placed over the outer end of the plummer 

 block to keep out the rain. The lubricant is replenished 

 once a month. 



At the bank, the skips of coal are weighed on an Avery 

 turntable weighing machine, Fig. 195. The rails are given 

 a down grade to the tippler, of 1 in 60, so that the skips can 

 run down hill alone. The empties are taken up hill again by 



Fig. 195. Avery Turntable Weighing Machine. 



, creeper chain. The side tipplers tip the coal on to a shak- 

 ing screen, placed at an angle of 1 in 4 ; from that the round 

 coal passes into a picking belt, while the slack falls into a 

 small hopper skip, and is carried up to the storage hopper. 



Dudley Colliery. 



This colliery belongs to the Dudley Coal Co., and is under 

 the management of Mr. Gr. Thompson. It has been working 

 for about 17 years on the bore hole seam, which is here 6ft. 

 3in. high and in which there are two bands of dirt; but only 

 5ft. 9in. are extracted, 6in. of dirty coal being left in the 

 roof. 



The downcast shaft is 624ft. deep, and the upcast 553. 

 The cages run on rope guides, two on the outer side and one 

 on the inner side. There are besides two dead ropes between 

 the cages to prevent the latter swaying too much. 



