Show Jive Give Wan Ya ng ng of 01 Fire Damp in Mine Glide Hundreds of t have k their trains bruins M t the mutter matter of 0 nr J. J jv certain of Ung the cause of ot such a large proportion ro of mine disaster disasters So No fur far no eons com petely reliable method has hal bt beer been found but It Is s believed ed that a devel development of lit the latest Idea will 01 the problem This ThIs' Idea consists In the he use Ulle of 11 u. u pair of telephones of tit n delicate kIn kind I one oue of if which h Is placed In the tappet galleries where the air I I known wn to tobe tobe be he pure pur while the other is fired In Inthe the lower workings Wires from each ench lend lead tn to a a n nat nl instrument j Beside each of of the telephones is a pitch pipe into which a n current of ot air airIs lr Is blown by a fan The t two pipes are tuned to give exactly the the same Bome musical musical musi musi- cal note So long tong as nil all Is well 11 only one D note Is 18 received and given out nut by the time central central cen cen- telephone but dire tv I v V fire damp dump occurs the air supplied the fan fun fanto to to the pipe in the lower workings becomes be he- comes changed in quality find end this a alters al al- tens the note very Cry slightly That Is the upper pipe of ot course courBe remains unchanged and the result rerun is s that Instead Intend of ot n a single BIngle clear note the central Instrument emits a n discordant noise which Immediately attracts the attention of the man iu lu charge warning warn warn- ing fag him ham that there Is fire damp In the lower lowe galleries Philadelphia Inquirer |