. Mechanical appliances, mechanical movements and novelties of construction; a complete work and a continuation, as a second volume, of the author's book entitled "Mechanical movements, powers and devices" ... including an explanatory chapter on the leading conceptions of perpetual motion existing during the past three centuries. 439. ELECTRICALLY HEATEDCHAFING DISH. The cylindricalbox under the dish is fitted with aresistance coil of iron wire insulatedwith asbestos packing. I82 ELECTRIC POWER AND DEVICES. 440. VIBRATING ELECTRIC BELL. A spring, R, is attachedat T to a fixed metallic rod, and
. Mechanical appliances, mechanical movements and novelties of construction; a complete work and a continuation, as a second volume, of the author's book entitled "Mechanical movements, powers and devices" ... including an explanatory chapter on the leading conceptions of perpetual motion existing during the past three centuries. 439. ELECTRICALLY HEATEDCHAFING DISH. The cylindricalbox under the dish is fitted with aresistance coil of iron wire insulatedwith asbestos packing. I82 ELECTRIC POWER AND DEVICES. 440. VIBRATING ELECTRIC BELL. A spring, R, is attachedat T to a fixed metallic rod, and presses against the rod T*. The current enters through the terminal, B, traversesthe bobbins, passes through T, through thespring, through T^, and makes its exit throughthe other terminal. The armature is at-tracted, and the point, P, fixed thereto drawsback the spring from the rod, T\ and inter-rupts the current ; but at the moment atwhich the point touches the spring, andbefore the latter has been detached from therod, T\ the electro-magnet becomes includedin a short circuit, and the line current, insteadof passing through the bobbins, passes throughthe wire, T, the armature and the rod T\The vibration of the armature breaks thecontact at T\. 441. PRINTING TELEGRAPH. The type wheel, /, driven byclockwork mechanism from the spring barrel, is placed on a shaft con-centric with the ratchet, k, which iscontrolled by pallets of the escape-ment, / /, attached to the per-manently magnetized armature, m,vibrated by alternating currentsthrough the electro-magnets, 0 electro-magnet, r, controllingthe printing escapement, is in thesame circuit, its core having anextension, w, and, being surroundedby a non-magnetic material, it is notoperated by the rapidly changingcurrents passing through 0 0, whichwork the type-wheel escapement;but when the key connected with any particular letter is struck, thecircuit is closed, sufficient magnetism accumulates in the core, w,to attract the arm
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Keywords: ., bookauthorhiscoxgardnerdexter18, bookcentury1900, bookdecade1910
