182 REPORT— 1873. 



action commences. It works at a speed of sixty to ninety strokes per minnte, 

 varying according to the pressure of the condensed air, the hardness of the 

 strata to be cut, or the expertness of the attendant. 



As to the quantity of work in " long wall," a machine can, under favoui- 

 ahle circumstances, cut 20 yards in an hour to a depth of 3 feet ; but we 

 consider 10 yards per hour very good work, or say 60 yards in a shift. 



This is about equal to the day's work of twelve average men ; and the per- 

 sons employed to work the machine are one man, one youth, and one boy, 

 who remove and lay down the road and clear away the debris. 



The machines are built so strong that they rarely get out of working con- 

 dition. Some of those now working at West Ardsley (and other places) have 

 been in constant use for three or four years. 



At that colliery there are about eight machines in use. One of the seams 

 is so hard and difficult to manage that it could not be done " by hand," 

 and the proprietors had to abandon, and did abandon it ; but now, by the 

 employment of the machines, it is worked with perfect ease. 



It is a thin cannel seam with layers of ironstone ; and the machines now 

 " hole " for about 1200 tons per week. 



The groove made by the machine is only 2 to 3 inches wide at the face, 

 and 1| inch at the back; whereas by bandit is 12 to 18 inches on the 

 face, and 2 to 3 inches at the back. 



Thus, in thick seams worked by hand, the holing is often done to a depth 

 of 4 feet 6 inches to 5 feet, and the getter is quite within the hole that he has 

 made ; and where the coal does not stick well up to the roof, or where there 

 is a natural parting, there is great difficulty and danger from " falls of coal." 



Referring to a section, it was observed that the angle of tlie cut is such 

 that, when the upper portion falls off, there is nothing for it but to pitch 

 forward into the road ; but by machine "holing" with a perfectly horizontal 

 groove, when the coal falls it simply settles upon its own bed, and has no 

 tendency to fall forward. 



The cost of applying coal-cutting machinery is an important part of the 

 question ; but it frequently happens that at old-established collieries there 

 may be surplus power, which can be utilized; but supposing that everything 

 has to be provided new, then the following may be taken as an approximate 

 estimate of the necessary outlay : — 



2 Boilers at .£500 each .£1000^ 



1 Steam-engine 1250 | 



10 Machines at ^150 each 1500 > say £5000 



Pipes, receiver, fixing and sundry other 1 -. ^rn 



outgoings J ■ ■ J 



This outlay would provide aU necessary power and plant for the regular 

 working of eight machines, with two in reserve ; and estimating that each 

 machine will cut 60 yards per day, the product in a 4-feet seam would be 

 85 tons per day, or per week say 500 tons per machine ; and 8 by 500 is 

 4000 tons. 



Now at this rate of expenditure and work done, an allowance of 2c?. per 

 ton would in three years liquidate the entire outlay. 



But there is no reason why the machines should be restricted to a single 

 shift daily ; indeed it is far more economical to work double shifts : there is 

 no additional outlay of capital ; and so far as depends upon the machinery, 

 the output might be easily increased to 8000 tons per week. 



We now come to the relative costs of cutting the coal by hand and by 



