GEORGE STEPHENSON. 87 



of all the wheels, attained by the use of horizontal connecting 

 rods ; and finally, a beautiful method of exciting the combustion 

 of the fuel by employing the waste steam, which had formerly 

 been allowed uselessly to escape into the air. Although many 

 improvements in detail were afterwards introduced in the 

 locomotive by Mr. Stephenson himself, as well as by his 

 equally-distinguished son, it is perhaps not too much to say 

 that this engine, as a mechanical contrivance, contained the 

 germ of all that has since been effected. It may in fact be 

 regarded as the type of the present locomotive engine." 



Explosions of fire-damp frequently took place in Stephenson's 

 lime, which were as disastrous in their results as those of more 

 modern times. In the year 18 14 an alarm was raised at one of 

 the Killingworth mines, that one of the deepest mains was on 

 fire. Stephenson coming to the pit-mouth ordered the engine- 

 man to lower him down the shaft. Getting six men to 

 volunteer to follow him, he speedily ran up a wall at the 

 aitrance to the main, which extinguished the fire and saved 

 many in the mine from a violent death. One of the men, by 

 name Kit Heppel, asked him at this time, " 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 pibncjis lives." This set him 

 a-thinking and v/orking, and in the course of 18 15 he endea- 

 voured to give his idea of a miner's safety-lamp a practical shape. 

 He described this lamp to the Committee of the House of 

 Commons, when sitting on the subject of Accidents in Mines. 

 He began by saying that he knew nothing of chemistry at the 

 time. " Seeing the gas lighted up, and observing the velocity 

 with which the flame passed along the roof, my attention was 



