MACHINES FOB CUTTING COAL IN MINES 155 



minute ; it is 3 feet 10 inches in diameter, and makes a clean cut of 3 feet 4 inches 

 deep by 3 inches thick, and from this space it entirely sweeps out the -whole of tho 

 coal as it revolves. The machine is propelled by a wire rope having one end secured 

 at the extremity of the face, and passing round a drum driven by the air-cylinders, or 

 by hand-gearing attached to the side of the machine. The whole is covered in with a 

 moveable sheet-iron casing to protect it from anything falling from the roof. One 

 man only is required to be in attendance on the machine, and another should follow 

 to sprag the coal as it is cut. 



With a pressure of 27 Ibs. of compressed air per square inch the machine has holed, 

 in a hard tough fire-clay seating, 25 yards in 40 minutes, and 24 yards' 1 foot of 

 strong solid coal in 55 minutes, with only 20 Ibs. pressure. A fair average rate of 

 work with 27 Ibs. pressure may bo stated at thirty yards per hour, 3 feet 2 inches to 

 3 feet 4 inches under aiid 3 inches thick, either in a seating or moderately hard coal. 

 The average rate of holeing by manual labour in the seam where it is now working is 



1419 



about 7 yards for a day's work equivalent to about nine men working a whole day to 

 do what the machine does better in two hours. The men have only to wedge or shoot 

 the coal down and clear it away, while the machine is taken to another bank to do its 

 work there. Infys. 1418 and 1419 the machine is shown in sectional elevations. 



Winstanley's Machine, The coal cutting machine of Messrs. Winstanley and 

 Barker is not essentially different from the machines already described. It consists of 

 a small frame running upon four wheels adapted to the colliery gauge, and carrying 

 two oscillating cylinders driven by compressed air or steam. On the crank-shaft and 

 xmderneath the frame is a pinion which gears into a very coarse-pitched toothed 

 wheel, the ends of the teeth being armed with, cutters. This cutting wheel can be 

 turned under the carriage when not required, and when placed ill position is brought 

 to bear against the coal by turning a handle into which it cuts, until the arm carrying 

 the wheel is at right angles to the carriage. The machine is slowly dragged forward 

 by means of a chain attached to a crab and worked by a boy. As the machine 

 advances, the miner in attendance drives wooden wedges into the cut to support the 

 coal, and when the machine is out of the way the wedges are withdrawn and the coal 

 falls. The machine itself only weighs 15 cwts., and will cut at the rate of 30 yards 

 per hour with a pressure of only 25 Ibs. per square inch, making a ' holing ' in the 

 coal 3 feet deep and only 2f inches high. The height of the machine is only 22 inches. 

 It has the disadvantage of being only able to cut on one side of the carriage^ but of 

 course it can be constructed to cut on the right- or left-hand side as may bo desired by 

 the purchaser. 



Hurd and Simpson's 39-inch self-acting, right and left-hand, variable height 

 coal-cutter was specially constructed for the Glass Houghton Coal Company to under- 

 cut in the blue stone band lying between two portions of the coal-seam. This 

 machine is worked on a somewhat similar principle to that of Winstanley and 

 Barker ; that is to say, the coal is undercut by means of a circular saw working at the 

 end of a moveable lever, but with this important difference, that in Hurd and Simp- 

 son's machine the cutter is placed in front, and can thus cut the coal right ahead of 

 the machine or on either side of it. The cutting wheel is slightly excentric, and the 

 machine hauls itself along by means of a chahi anchored ahead of it ; for as the 

 cutter revolves, being an excentric, the teeth on one portion of the periphery would 

 revolve without touching the coal, but at this time the self-acting hauling gear comes 

 into play, the machine advances, and the cutters get a fresh feed on the coal. This 

 coal-cutter is 30 inches high over all, and exits to a depth of 3 feet 3 inches. 



