What the workmen, not less than the coal-owners, eagerly desired was a lamp that should give forth sufficient light, without communicating flame to the inflammable gas which accumulated in certain parts of the pit. Something had already been done toward the invention of such a lamp by Dr. Clanny, of Sunderland, who, in 1813, contrived an apparatus to which he gave air from the mine through water, by means of bellows. This lamp went out of itself in inflammable gas. It was found, however, too unwieldy to be used by the miners for the purposes of their work, and did not come into general use. A committee of gentlemen interested in coal-mining was formed to investigate the causes of the explosions, and to devise, if possible, some means of preventing them. At the invitation of that committee, Sir Humphry Davy, then in the full zenith of his reputation, was requested to turn his attention to the subject. He accordingly visited the collieries near Newcastle on the 24th of August, 1815, and at the close of that year, on the 9th of November, 1815, he read before the Royal Society of London his celebrated paper "On the Fire-damp of Coal Mines, and on Methods of Lighting the Mine so as to prevent its Explosion."
But a humbler though not less diligent and original thinker had been at work before him, and had already practically solved the problem of the Safety-lamp. Stephenson was, of course, well aware of the desire which prevailed in the colliery districts for the invention of a lamp which should give light enough for the miners to work by without exploding the fire-damp, and the painful incidents above described only served to quicken his eagerness to master the difficulty.
For several years he had been engaged, in his own rude way, in making experiments with the fire-damp in the Killingworth mine. The pitmen used to expostulate with him on these occasions, believing the experiments to be fraught with danger. One of the sinkers, called M'Crie, observing him holding up lighted candles to the windward of the "blower" or fissure from which the inflammable gas escaped, entreated him to desist; but Stephenson's answer was, that "he was busy with a plan by which he hoped to make his experiments useful for preserving men's lives." On these occasions the miners usually got out of the way before he lit the gas.