CORRIMAL-BALGOWNIE COLLIERIES. 207 



the column of water in this shaft, and it is intended that they 

 shall pump some 600 gallons per hour from a lower level, de- 

 livering it into the pipes leading to daylight. While sinking, 

 the shaft was divided into two compartments, a downcast and 

 upcast; the latter was formed by half-inch tongued and 

 grooved lining boards, nailed to 9ft. long buntons placed 6ft. 

 apart. The upcast compartment was carried up higher than 

 the mouth of the downcast, and the air was further heated 

 by the exhaust from the steam pump, which was led into it. 



Round the mouth of the shaft is an 18in. thick brick wall, 

 16ft. square, built up from the solid rock. The brick cylinder 

 lining the shaft is built up inside this square, which has a few 

 gaps left in it when they touch, so as to tooth in the bricks of 

 ihe cylinder. The corners are filled in with concrete. The 

 liead frame is made of wood (Fig. 127), the sills of which rest 



Fig. 128 

 Fisher's 

 Clip- 



on the brick wall. The sinking engine, when finished with for 

 this purpose, will be compounded (by replacing one of the 

 cylinders with a larger one), and used for hauling purposes. 

 Steam is raised in two Babcock and Wilcox boilers. Room for 

 two more is provided should they be required in the future. 



The clips used on the incline consist of two slightly 

 tapered jaws, threaded on to a ring at their narrow ends, and 

 kept together by a collar that encircles them, but which can 

 be slid up or down according to whether it is desired to loosen 

 -or tighten the grip (Fig. 128). New clippers-on are apt to 

 make mistakes, and allow the skips to run down the incline 

 without properly fastening them to the rope. To prevent 

 danger under such circumstances, the runaway switch is con- 

 structed near the top of the incline on the full track side (Fig. 

 129). (A) is the main track, (B) the side track, which has a 

 uphill. The switch (f) is kept in position for the skips 



