108 STEPHENSON'S EXPERIMENTS ON FIRE-DAMP. CHAP. VI. 



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 

 was formed at Sunderland 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 repu- 

 tation, was requested to turn his attention to the subject. 

 He accordingly visited the collieries near Newcastle on 

 the 24th of August, 1815 ; and on the 9th of November 

 following, he read his celebrated paper " On the Fire- 

 Damp of Coal Mines, and on Methods of lighting the 

 Mine so as to prevent its Explosion," before the Eoyal 

 Society of London. 



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 anxiety 

 which prevailed in the colliery districts as to the in- 

 vention of a lamp which should give light enough for 

 the miners to work by without exploding the fire-damp. 

 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 his 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 

 Stephensoii'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. 



In 1815, although he was very much occupied with 



