

NEW AVINMXG OR SEA PIT. 293 



~a ring that encircles it. Fig. 189 shows the hook both closed 

 and open; (a, a 1 ), are the two levers pivoted on (b), and held 

 in place by the collar (c), and copper rivets passing through 

 to a tongue piece. AVhen the hook is pulled up through the 

 thimble, the collar (c) is pushed down, the copper rivets 

 .sheared, the weight of the cage and load cause the jaws to 

 cpen, and the wings catch on the top of the thimble. 



Fig. 189. Walker's Safety Hook. 



The coal is tipped from an end tipple on to a shaking 

 screen, the top part of which is covered with sheet iron; then 

 there are some bars, and finally thick iron wire mesh. The 

 slack is weighed on a Billy Fair Play, and then stored in a 

 coal box, to which it is taken by a conveyor, when there are 

 no trucks ready to train it away. The round coal is weighed 

 on two Avery machines. Beams are placed across the plat- 

 form of the machine, and rods from these pass down to a box 

 below, into which the coal falls from the end of the picking 

 belt. The tokens, as they are taken off the skip, are clipped 

 to a small carrier, and pushed along a wire leading to the 

 weighing-room . 



Hetton Colliery. 



This colliery is situated at Carrington, a suburb of New- 

 castle, and is owned by the Hetton Coal Co. Ltd. It is about 

 24 years old, and has been for many years under the charge of 

 the present manager, Mr. A. Mathieson. The coal mined is 

 under the ocean and tidal waters, and one of the interesting 

 features of this colliery, as also that of the adjoining Stockton 

 colliery, now closed down, is in connection with shaft sinking 

 through quicksand and clay. The shafts are 280ft. deep, and 

 are tubbed from the surface to within 60ft. of the bottom. 

 The main shaft is 15ft. lOin., and the air shaft 14ft. in dia- 

 meter. The thickness of the cast iron segments which go to 

 form the rings is the same from top to bottom, namely, IJin. 

 There is a slight difference in the styles of the tubbing in the 

 two shafts. The segments for the main shaft were rough 

 castings, with only a lin. face at the back, where the seg- 

 ments above and below were able to come in contact, the rest 

 of the joint being occupied by half-inch thick lining boards, 



