NEWCASTLE A. AND B. PITS. 285 



comes down to within 2ft. of the floor. The coal cutting is 

 done by means of a Sullivan machine, which requires 30h.p. 

 to drive it. "it makes a cut 6ft. deep and 4in. high, and is 

 flitted along- the gateways on a self-propelling trolley. 



Coal is shot down in some of the pillar workings, with 

 bobinite, and in the bord workings with ordinary blasting- 

 powder. Naked lights are used below except in some of the 

 pillar workings, where safety lamps are employed. The open 

 lamps burn tallow, which the miners themselves provide. 



When testing the depth of cover in those workings under 

 the ocean, boreholes have to be put up, and for that purpose 

 a serrated bit of Jin. steel is used, having 8 teeth, set alter- 

 nately in and out, so as to give a clearance of fin. The ver- 

 tical portion of the teeth is Jin., while the bevel is liii. This 

 crown cuts out a core lin. in diameter. The core barrel is 

 made in two lengths, 2ft. Gin. and 5ft. At the end of the 



Fig. 185, Stayner's A ]N T ut. 



core barrel, an ordinary solid rod of square cross section is 

 screwed in; these rods are made in 2ft. 6in. lengths. The 

 rod is rotated by a ratchet worked by hand. Stayner's 

 patent nut (Fig. 185), is used with this appliance, which does 

 away with the necessity of unscrewing the feed screw, since 

 the nut can be caused to slide back when desired to add a 

 fresh length of rod. The bottom of the ratchet is fitted into 

 a small hole in an iron plate placed on the ground, so as to 

 give it sufficient support. 



The main and tail rope system of haulage is used in the 

 main roadways, a set of 45 skips travelling at the rate of 14 

 miles per hour. Skips are gathered to the flats by ponies 

 and horses, varying from 12 to 15 hands high, according to 

 the place they have to work in. When a train of skips has 

 been pulled up on the kip, a knock off bar (Fig. 186), fixed 

 across the line, hits the devil, or detatcher, which is a bell 

 crank attached to the end of the leading skip, and draws out 

 the pin of the shackle that connects the end of the rope with 



