On Safe-Lamps for Coal Mines. 4o9 



ihe philosopliical journals of last month ; but I shall spealc in 

 <!etail of one produced by a Mr. Stephenson, engine-wright at 

 Killingwoitli Colliery, which met with universal approbation. 

 This is a small copper lamp, of a semi-globular form, with aa 

 outer case of the same shape : round the lower part of this case 

 are numerous small holes, by which the air is admitted, and after 

 passing between the two cases, escapes through a circle of similar 

 orifices surrounding the wick, and feeds the flame : this simple 

 apparatus is cpvered with a glass chimney, which fixes in a rim 

 so as to 1)6 rendered air-tight, and the chimney protected by a 

 tin covering pierced full of holes, at once to emit hght and save 

 the glass from external injury. In this manner combustion is 

 carried on while the air is sufficiently pure for its sup))ort; but no 

 sooner is it contaminated by carburetted hydrogen up to the 

 firing point than the flame gradually dies out uithout explosion ; 

 and should the inflammable gas be precipitated down the chim- 

 ney by any unforeseen accident, the azotic gas accumulated 

 above the flame is found equal to extinguish it. The height of 

 this lamp, of which the inclosed correct tho\ioh rough drawing 

 (Plate VIII. fig. 11) will convey a just idea, is twelve inches, 

 and cost rmder five shillings. Of its great utility in places of 

 danger, the following experiment seemed to carry the strongest 

 conviction to every practical miner present. A quantity of 

 carburetted, hydrogen, obtained from a blower in Kiilingworth 

 Colliery, vvas pressed from a bladder so as to enter through the 

 small holes near the bottom of the lamp, the contents of another 

 bladder being discharged into a ga'Ometor inverted at the same 

 time over t e chimney : the flame in the lamp gradually died 

 awav,as was the case in a previous trial, and without the gas aljove 

 it being inflamed ; but no sooner was a candle introduced into 

 the gasometer than an explosion took place. 



From what has been already said, together with the inclosed 

 section, an invention nearly similar to Sir II. Davy's will be 

 immediately recognised; but that it has not been pirated fiom 

 that gentleman is a fact known to most of the mine owners 

 Iiere ; for on the 3d of November the Reverenil Mr. Ilodgen 

 of Haworth, and Dr. Grey of Wearmouth, communicated to a 

 verf full meeting of the coal trade held at the Assembly-rooms, 

 the contents of letters just received by them from Sir Hinnphry, 

 reciting the particulars of his newly-invented safe-lamps ; and to 

 the same company Mr. R. Lambert, chief agent for Kiilingworth 

 and other mines on this river, mentioned the discovery made by 

 Stephenson, who is employed by him as an engine-wright, 

 observing, at the same time, that his lamp had been taken into 

 rhe pits, and found to answer the intended purpose. Sir Hum- 

 phry 



