Safety-lamp Controversy. 65 



ones above, and the flame burnt in them at a distance from the 

 apertures with diminished light, and was extinguished in ex- 

 plosive mixtures by the azote and carbonic acid formed in com- 

 bustion. He next used systems of safety- tubes and safe-9."ir ca- 

 nals, both below and above ; and he gradually increased the 

 number, and reduced the length of his tubes and canals, till he 

 was led to adopt a tissue permeable to air aild light^ and imper- 

 meable to the explosion of fire-damp, even when red-hot. He 

 first made air-feeders and chimneys of this tissue, and then 

 adopted it as the guard of flame. From the first sitting of the 

 Royal Society, the 9th of November that year, he regularly com- 

 municated the progress of his researches to that illustrious body ; 

 and before the 31st of December 1815, he presented to the mi- 

 ner the wire-gauze safe-lamp, which not only affords a safe light 

 in explosive atmospheres, but which even consumes the element 

 of destruction. 



This simple statement, which might be increased ten*-fold by 

 authorities and details, is given for the purpose of contradicting 

 an opinion which has appeared in the form of a resolution of 

 certain persons at Newcastle, Charles J. Brandling, Esq. in the 

 chair ; to this effect : — " That it is the opinion of this meeting. 

 That Mr. George Stevenson having discovered the fact that ex- 

 plosion of hydrogen ga? will not pass through tubes and aper- 

 tures of small dimensions, and having been the first to apply that 

 principle in the construction of a safety-lamp, is entitled to a 

 public reward." 



. To show that there is ajiy foundation for this opinion, it ought 

 to be proved, 



1st. That the first lamps which this person sold as safe-lamps 

 were founded upou the principle of explosion not passing through 

 tul)es and apertures of small dimensions. 



2dly.That this person had made, and communicated to credible 

 witnesses, a practical demonstration of this principle before the 

 middle of October 1815, or had published it before November 

 1815. 



Now the lamps which Mr. G. Stevenson sold in January 1816, 

 had in them neither safety-tubes nor safety-apertures. One of 

 three bought for the Wallsend colliery is preserved in the Royal 

 Institution. It is furnished with holes from one-eighth to one- 

 tenth of an inch in diameter, connecting an air chamber below, 

 and has a chimney with holes in it of from one-third to one- 

 fourth of an inch in diameter above, and it produces the explosion 

 of explosive mixtures almost as readily as a common candle. The 

 apertures are loo many and the flame too near t/iem, to render it 

 safe by a diminished circulation of air ; and infinitely too large 

 to render it safe by the cooling effects of their sides. The first 



Vol. 51. No. 237. Ja7i. IBIS. E lamp 



