CHAI>. VII. DR. CLAXNY'S LAMP. 107 



Heppel, who had been present and helped to build up 

 the brick wall by which the tire was stayed, though 

 several workmen were suffocated. Heppel relates that, 

 when down the pit some days after, seeking out the 

 dead bodies, the cause of the accident was the subject 

 of some conversation between himself and Stephenson, 

 and Heppel then asked him, " Can nothing be done 

 to prevent such awful occurrences?" Stephenson 

 replied that he thought something might be done. 

 " Then," said Heppel, " the sooner you start the better ; 

 for the price of coal-mining now is pitmen s lives." 



Fifty years since, many of the best pits were so full 

 of the inflammable gas given forth by the coal, that 

 they could not be worked without the greatest danger ; 

 and for this reason some were altogether abandoned. 

 The rudest possible methods were adopted of producing 

 light sufficient to enable the pitmen to work by. The 

 phosphorescence of decayed fish-skins was tried ; but this, 

 though safe, was very inefficient. The most common 

 method employed was what was called a steel mill, the 

 notched wheel of which, being made to revolve against 

 a flint, struck a succession of sparks, which scarcely 

 served to do more than make the darkness visible. A 

 boy carried the apparatus after the miner, working the 

 wheel, and by the imperfect light thus given forth he 

 plied his dangerous trade. Candles were only used in 

 those parts of the pit where gas was not abundant. 

 Under this rude system not more than one-third of the 

 coal could be worked ; and two-thirds were left. 



What the workmen, not less than the coal-owners, 

 eagerly desired was, a lamp that should give forth suffi- 

 cient light, without communicating flame to the inflam- 

 mable gas which accumulated in certain parts of the 

 pit. Something had already been attempted towards 

 the invention of such a lamp by Dr. Clanny, of Sunder- 

 land, who, in 1813, contrived an apparatus to which he 

 air from the mine through water, by means of 



