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Show Electric Lamp for Miners Gains Favor rrn HE old-fashioned flame safety I lamp used for illuminating the JL miner's working place is fast going go-ing into the discard, according to the United States bureau of mines, which estimates that about 100,000 electric cap lamps are now in use. In 1911 approximately 45,000 flame lamps and no electric lamps were being be-ing used in the Pennsylvania bitlmi-nous bitlmi-nous mines, which were then producing produc-ing 35 per cent of all the soft coal mined In this country ; by 1918 the flame lamps bad decreased to 17,000 whereas electric lamps totaled nearly '48,000. In Great Britain during the same years the total of 723,934 flame lamps decreased to 590,185 and the electric lamps gained rapidly from 4.29S to 150,521. No later reliable figures fig-ures are at hand. "Though coal was known to the an-ients. an-ients. the earliest mention being cred-ted cred-ted to Theophratus, a Greek writer, about 371 B. C, the first known record of coal mining was made in England about 11S0 A. D.," the bureau of mines points out. "It was at least 600 years later before the safety flame lamp was introduced. At first coal was undoubtedly obtained from out-:rops. out-:rops. and mining was done by day light. As the outcrops were worked out, the miners advanced gradually further and further into the coal bed, until the openings became quite extensive ex-tensive and somewhat resembled the small mines of today. "Even the approximate date when lamps or tallow candles were first used in mines is unknown, but some source of artificial light was probably used In metal mines long before coal mining began. Agricola, in a treatise on metal mining published In 1556, gives sketches that show conditions prevailing prevail-ing in his time. "One of these sketches shows a miner min-er carrying a lamp which apparently consisted of a wick dipped In grease or oil of some kind. "Dr. William Keid Clanny was undoubtedly un-doubtedly the first to design a closed-flame closed-flame lamp and the first to build a lamp and to have It actually tested underground un-derground in a gaseous atmosphere. His first model was about 1811. George Stephenson made lamps of three distinct dis-tinct models and tested them underground under-ground in 1815. The first flame safety lamps devised by Sir Humphry Davy were put in service January, 1816 ; by the end of that year they were In fairly general use. |