HED130N GRETA COLLIERY. 



335 



is, in consequence, simple, as shown in Fig. 210, since the re- 

 sultant of forces conies chiefly 011 the vertical members. 



The cage holds two skips, and has a tank for baling pur- 

 poses. On account of the inclination of the shaft, winding has 

 to take place from different levels. The main engine at No. 1 

 tunnel was manufactured by R. and J. Morison and Bearby, 

 of Newcastle (N.S.W.), and has 22in diameter cylinders, with 

 4ft. stroke, and a single 6ft. drum divided in the centre by a 

 brake path. The coal is worked for about 16ft. thick in two 

 workings. Above No. 2 level the bords and pillars are each 



ig. 210. Pit Head Frame. 



8 yards wide, but below No. 2 level the pillars are 20 yards 

 wide. 



The bifold safety lamp is used throughout this mine. These- 

 have two round wicks and double gauzes, but no deflector. 

 They are made by Messrs. Abbott, Roby and Naylor, of 

 Wigan, England. 



The ventilation is carried out by means of a furnace at the 

 surface. This is built at the foot of a stack (Fig. 211}, into 

 which the air drift leads. A brick partition divides the up- 

 cast from the products of combustion for a short distance, 

 and then they meet higher up, to escape at the top of the 



