ON COAL-CUTTING MACHINERY. 



181 



tunate persons died from the effect of the " afterdamp ; " two of the mea 

 were fortunately saved by a very smaU current of air which was turned upon 

 them by a brattice cloth, and which supported life until they were released*. 



If the compressed air-pipes had been in those workings at that time, it is 

 not unreasonable to believe that very few, if anj^, of those twenty-live men 

 would have succumbed. 



There is another useful purpose incidental to the use of coal-cutting 

 machinery in mines, which it is worth while to notice ; and that is in the 

 event of a jnt being on fire. 



At West Ardsley a " blown-out shot " ignited the gas and set fire to the 

 goaf. It extended to the face of the coal, and had taken strong hold of it, 

 and the whole pit was in the greatest danger. There is a large water-tank 

 at the surface for suppljdng the boilers and coke-ovens ; and the manager 

 promptly connected the air-pipes to the water-tank and turned the water 

 into the fire. 



In less than an hour the fire was completely extinguished without any 

 serious damage. On a previous occasion the same colliery was on fire, and 

 had to be closed up. That fire cost us many thousands of pounds. It hap- 

 pened before the introduction of the coal-cutting machinery. 



Compressed air is also becomiug extensively used for " hauling," and with 

 very great advantage. Small engines can be set up wherever convenience 

 or necessity may require ; they are portable and removable at a trifling 

 expense, and are available where no other mechanical power for traction 

 can be obtained. 



It is also valuable for pumping water, and " drilling " the holes where the 

 coal has to be " blasted," or broken down by the hydraulic press. 



Enough has been said respecting this remarkable and diversified power to 

 justify the expectation that it is the key to vast and important improvements 

 upon the present system of working coal ; and bearing in mind that the 

 wealth, the power, and the greatness of this nation depend primarily upon 

 an abundant supply of coal, it is hardly possible to overrate the importance 

 or overvalue the advantage which this power places at our disposal. 



I now turn to the consideration of the machine for cutting the coal, which 

 has for several years been employed at West Ardsley without any interrup- 

 tion. [A model and photograph were exhibited to show its form and con- 

 struction.] The weight is about 15 cwt. for a machine of ordinary size, its 

 length 4 feet, its height 2 feet 2 inches, and the gauge 1 foot 6 inches to 

 2 feet ; it is very portable and easily transferred from one benk to another. 



The front and hind wheels of the machine are coupled together in a similar 

 manner to the coupled locomotive engines. The " pick," or cutter, is double- 

 headed, whereby the penetrating power is considerably increased. 



The groove is now cut to a depth of 3 feet to 3 feet 6 inches at one course, 

 whereas by the old form of a single blade we had to pass the machine twice 

 over the face of the coal to accomplish the same depth. The points are loose 

 and cottered into the boss ; so that when one is blunted or broken, it can be 

 replaced in a few moments. This dispenses with the necessity of sending the 

 heavy tools out of the pit to be sharpened, and is an immense improvement 

 upon the old pick. 



When all is in readiness for work, the air is admitted and the reciprocating 



* I am informed that at the accident at the Oaks Colliery, near Bai*n8ley, in 1866, 

 forty-five persons were found dead in one place, and seventy in another, vfIio were lost for 

 want of a little air ; and it is bolieved tliat many more al that time died from the same 

 cause. 



