RI 2371 Why Miners' Portable Electric Lamps Require Safety Devices

The Buresa. ot Mines at its Pittsburgh Station conducted tests aa earl7 a.a 1911 looking into the satety of miniature electric bulba. The first teata were maie with bulbs euch as were being sold with the partly developed lamps then on the market. 'l'he.sa aarly teats demonstrated the da.nger of using minia.tu:re bulbs in explosive mine atmospheres unless the current that enet gized the glow!ng filament was in aome minner inter.N.ptecl if the glass surrounding the filanant should be broken.