204: THE FIRE-DAMP'S FAMILY CIRCLE. 



committee ; but I have one of our working lamps with me. 

 He told me that it would burn safely in an explosive mixture. 

 I first tried it in an explosive mixture on the surface, and 

 then took it into a mine; and to my astonishment and de- 

 light it is impossible for me to express my feelings at the 

 time when I first suspended the lamp in the mine and saw it 

 red-hot. If it had been a monster destroyed, I could not 

 have felt more exultation than I did. I said to those around 

 me, " We have at last subdued this monster." ' 



Mr. Buddie then relates how, subsequently, Sir H. Davy 

 went down the G pit of the Wallsend colliery, where he was 

 shown all the gradations of explosive mixture; from a slightly 

 contaminated atmosphere, just enough to produce an elonga- 

 tion of candle-flame, to where pillar working was going on, 

 and large amounts of gas were accumulated as in a reservoir. 

 ' Here,' said Mr. Buddie, ' we took the lamp, and suspended 

 it for a length of time, till it was red-hot, during which we 

 also exposed it to the ordinary impulse of currents of air ? and 

 in different parts we tried the lamp in a red-hot state for a 

 considerable period of time. He then explained to us the 

 danger of exposing the lamp to a strong current of gas, or 

 even to a strong current of explosive mixture, as it would risk 

 the passing of flame through the gauze, but he pointed out a 

 remedy at the same time namely, a tin screen.' 



From this statement it is evident that Davy was aware of 

 the conditions under which the gauze covering was not a 

 protection; a fact which, according to Mr. Buddie, he strongly 

 insisted upon at a previous time namely, when Mr. Buddie 

 accompanied him to one of the Earl of Durham's collieries, 

 where a large ' blower,' or natural issue of inflammable gas, 

 presented facilities for testing the permeability of the safety 

 gauze. Having directed the gas jet against the safety sheath, 

 and caused flame to pass, Davy is said to have commented on 

 the fact in the following words : f Now, gentlemen, you see 

 the nature of the danger to which you are exposed in using 



