Crystal Palace International Electric Exhibition 1881-82

102 455—Gregory Skrivanoff, 32, Rue Vignon, Paris. Indicators for Hotels, with accessories allowing of an economy of 50 per cent, in wires and fixing ; various motors for toys. South Nave. 456 —Léon Somzée, 217, Rue Royale, Brussels. Apparatus for indicating the presence of firedamp. 1. The application to ordinary mining’ lamps for mining purposes of two metallic plates, bands, or wires of different capacity of dilatation, rendered suscep- tible to slight variations of temperature, placed in connection with an electriccurrent, which shall at a certain temperature give alarm (jy ringing a, bell. On© band, may loo steel cincl tli© otlioi zinc, united by a soldering of tin. If firedamp is present in the air feeding the lamp it produces an excess of heat in its interior : the metallic plates expand and close the electric current. 2. The use of glass-tubes subjected to heat, in connection with a thermo- electric pile indicating the difference o£ heat between the two tubes, on© of which, is filled with, air from tlie outside of the mino and the other with the air of the mine. 3. An electro-chemical mode of detection by the use of the electric light in combination with, chlorine, causing by explosive action the vibration of tlie membranes of one or more telephones. 4. The use of sonorous tubes of certain lengths, placed over a flame produced by the combustion of pure air, and which tubes give normally no sound ; but as soon as firedamp is present the Same grows longer, the tubes are subject to heat, and then give forth sounds by causing a vibrating tongue, within the tube, to expand, and so produce certain notes and thus give alarm. 5. The application to lamps for mining" purposes of a little tube filled with pieces of coal compressed therein, the extremities of the tube mounted in metal. The coal is compressed in the tube by a screw and the tube’s metallic extremities are in connection with, the wires of a galvano- meter. If firedamp is present in the air feeding the lamp, it produces an gxcgss of heat in tb.6 interior ; th.© coal m tlie tube absorbs this excess lieat and. Ijscomss Isss conducting’. This thermoscope, placed in connection with, an electric current, will then indicate the composition of the air in the mine. 6. Improve- ments consisting of a glass vessel, containing mercury covered with a partition of porous earth, having in the middle a central tube communicating with, th© mercury in tlie vessel. 1 lie pressure of air Toeing equal in tli6 tubs and vessel, tlie moi cm y lies at tlie same level in both; but when firedamp is in the air it penetrates through the porous partition and presses on the surface of the mercury, tlie Is vol of winch. is raised in th.6 tubs, whore it toucliss a platinum-wire in contact with, an electric current and rings an alarm. Southern Gallery. 457.—George Vian, 53, Rue de Chateaudun, Paris; London Representatives, Castel & Latta, 3, Lombard Court, E.C. Electric Machine, specially constructed for exploding dynamite from a distance in mining and. subaqueous works. I ac-simile of Dynamite Cartridges, Detonators, &c., suitable to be used in connection with the above. Western Gallery.