Mr. Spelling, an engineer of the Whitehaven coal mines, having observed that the fulminating damp could only be kindled by flame, and that it was not liable to be set on fire by red-hot iron, nor by the sparks produced by the collision of flint and steel, invented a machine called a steel-mill, in which a wheel of that metal is turned round with a very rapid motion, and, by the application of flints, great plenty of sparks are emitted, which afford the miners such a light as enables them to carry on their work in close places, where the flame of a candle, or a lamp, would, as has already happened in various instances, occasion violent explosions. In that dreadful catastrophe, the explosion of the Felling colliery, the particulars of which will be hereafter detailed, it will be seen that mills of this description were employed, in searching for the remains of the victims of the sad disaster; but this event happened before the invention of Sir Humphrey Davy’s safety-lamp, a discovery which, while it affords a more certain light, holds out every security to the miner against accidents which, without such a resource, might still be superadded to those already recorded, as arising from the flame of a candle or lamp. A greater number of mines have, however, been ruined by inundations than by fires; and here that noble invention, the fire-engine, displays its beneficial effects. It appears from nice calculations, that it would require about five hundred and fifty men, or a power equal to that of one hundred and ten horses, to work the pumps of one of the largest fire-engines, having a cylinder seventy inches in diameter, now in use, and thrice that number of men to keep an engine of that size constantly at work. It also appears that as much water may be raised by such an engine, as can be drawn, within the same space of time, by twenty-five hundred and twenty men with rollers and buckets, after the manner long practiced in many mines; or as much as can be borne on the shoulders of twice that number of men, as is said to be done in several of the mines of Peru. So great is the power of the elastic steam of the boiling water in those engines, and of the outward atmosphere, which, by their alternate actions give force and motion to the beam, and through it to the pump rods which elevate the water through tubes, and discharge it from the mine!