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Show Delicate French Invention Used in War Put to Remarkable Re-markable Uses WASHINGTON, D. C, April 9. After a series of Important teats with tho gcophone, a listening device into in-to detect and locate enemy underground under-ground operations, the bureau of mines, department of tho interior, announces an-nounces that thl3' delicate instrument may bo put to. a number of remark-ablo remark-ablo uses in mining and other industries. indus-tries. The most extraordinary result ot of these tests is that the bureau of mines men have been able, not only to hear and locate sounds ' through the earth, but havo actually understood talking through fifty foot of solid coal and havo detected tho human volco fully 160 feet away. What this moans in the near future can only bo conjectured. con-jectured. An engineer of tho bureau was able through 300 feet of coal to distinguish nine out of ten different mining tools that wero used at different differ-ent times, so characteristic aro tho sounds. In 'one mine whero expori-monts expori-monts wero being made at tho face of a tunnel, the mine foreman, who was listening, heard workmen In another tunnel preparing to blast, and ordered tho cnglneera to rotlro until the blast was fired. Tho sounds wero so clear ho did not rcallzo that the tunnel hcadincrs wore over 300 feet anart. Valuable In Jtescuc Work. The greatest value of tho gcophono In mining, so far as known, will bo In connection with rescuo work in mines. Quite frequently miners aro entombed in coal mines following explosions, and theso may may bo located quiclky and accurately through tho geophonc. In metal mines alHo, whero men nmy be Imprisoned behind fnlls or bo barricaded bar-ricaded in Gomo part of tho mlno to which thoy havo retreated in order to protect themselves from tho fumes or fire these, too, may bo rescued through prompt location. When the bureau first began Its experiments ex-periments with tho goophono, It was questionable whothor tho gcophono could hear sounds far onough away to make it practicable Tho oxperl-j ments show that sounds can bo dotoct-od dotoct-od through tho earth a distance of l.EOO foot In a mined-out area in a coal mine; through oolid coal 2,000 feet and through solid rock about half u mile. Gcophone of Great Practical Value. Tho Keophono Is nlso of great practical prac-tical valuo In metal mines whero two tunnels havo to be connoctod. At times, In splto of as correct surveying as is possible, tho two tunnel headings head-ings fall to como togethor. Just recently re-cently bureau of mines cnglnoors werej In a mlno whero the two ends of tho tunnel failed to moot, and the geo-j phones, locating the error, showed mo minora tho right direction. Observations with tho gcophono I have also been made at mines which were on fire, whero it was found that the fire made noiso enough to be heard somo distance, olther because of I its drawing air or the breaking off of bits of coal and slate, The geophones by thus locating the firo gives information infor-mation which may onablo thc mine management to erect fire stoplng In the proper places or to make a direct attack on the fire, as for example by drilling holc3 for Injecting water to tho seat of the fire. Guiding of Drills. I It Is also tho custom In somo mining min-ing localities to drill a hole from the surface Into a mine to carry plpo lines or cables. Oftentimes theso drill holes do not go to tho right places, and it Is with considerable, difficulty arid ex-ponso ex-ponso that. tunnels" are driven to meet tho. drill hole. With tho aid of tho gcophone, tho drills can bo guided better, especially slnco drilling can bo detected for nearly a mile. Very satisfactory results havo boon obtained in attempts mado to locate leaks In water mains. Tho water clr-I clr-I culatlng In tho ordinary city main can I bo heard with tho geophones when they arc placed on tho surface, ton or twelve feet above the pipe. In the I I business district of Pittsburg, ono leak 1 was located within a few minutes, al-! al-! though tho water department had 1 been trying to find it for two weeks. |
