Show To Detect Gas In Mines MinesA I IA A new electrical instrument to detect de de- detect explosive gas In mines has Just I de-I been patented Such an Instrument is necessary because of the greatly Increased increased In in- I creased use of at electric mine lamps In Instead Instead instead In- In stead of or the time old-time Dav Davy safety lamps The Davy lamp gave the min miu mIner miner er warning of ot the presence of ot gas but the electric flash lamp of ot course does not The new detector consists of two glowing electric wires connected In series One wire Is treated so as to burn hurn more brightly In laden gus air than In pure air In perfectly pure pureair pureair pureair air the two wires g gloy y with exactly the same brightness By noting the I difference In the brightness of ot the two indicators the miner can not only detect detect detect de de- the presence of ot dangerous gas but can also tell almost exactly how much of ot It Is 13 present J 4 |