Mr. Stagg 071 the prevention of Explosions in Collieries. 351 



ties an idea that may be of some value, and, possibly, in abler 

 hands, may be rendered available. 



It appears that though the safety lamp possesses many merits, 

 and has doubtless been of immense service, yet, under cer- 

 tain circumstances, it fails to offer perfect security; and this 

 has led me to imagine that the light produced by a current of 

 galvanic electricity might be applicable. 



This could be done by having the wires from a galvanic 

 battery conducted into the middle of a strong glass tube, in 

 the usual way of obtaining a constant electrical light. All 

 access to external air or inflammable gases might be prevented 

 by carefully and hermetically sealing the parts where the wires 

 enter, and, on the battery being charged, a sufficient and safe 

 light would in all probability be obtained. The cost of such 

 a method would not be so great as the present plan of Davy 

 lamps and candles, with all the cost of repairs, &c., and the 

 immense loss of property consequent on an explosion. Va- 

 rious wires, all proceeding from the battery, could be carried 

 in different directions so as to light the whole mine, and even 

 the most dangerous parts, at the same time. 



The light obtained could also, at all events, be made, by 

 means of a sufficiently powerful battery, at least equal to that 

 of a Davy lamp. 



The only objection, that of the liability of the glass tube to 

 be broken by the dropping of water, &c. from the roof, could 

 be obviated by placing a shield over such a glass tube, and 

 still more effectually by inclosing the tube in a second one, 

 which would be destroyed without affecting the interior one; 

 for which suggestion I am indebted to Dr. White, an eminent 

 physician in Newcastle. 



I had the happiness of meeting Prof. Liebig in Mr. Rich- 

 ardson's laboratory in Newcastle, a few days after the above 

 accident, and mentioned the suggestion to him, of which he 

 expressed a favourable opinion, but said that he believed it had 

 been proposed many years ago. 



The idea, however, being new to myself, I hope you may 

 so far approve of the same as to give the above few remarks a 

 place in your valuable Journal. When meeting the eyes of 

 the parties more conversant with electrical phaenomena, it may 

 be worked out so as to become, in their hands, an efi'ectual 

 means of saving the lives of our miners. I beg to subscribe 

 myself, 



Yours respectfully, 

 Newcastle-on-Tyne, October 7, 1844. J. D. Stagg. 



