Report on Telegraphs and Apparatus Volume 2

Report on Telegraphs and Apparatus Volume 2

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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1876 edition. Excerpt: ...upon a vertical support placed within a multiplier-coil traversed by an induction-current. These two magnets are provided at one of their extremities with a little ink-receptacle and at the other with a small brass hammer. By means of a regulating-magnet placed in front, they are so arranged that a current passing in one or the other direction puts in motion the first or the second of these magnets and establishes in either case a contact between the ink-holder and a baud of paper which passes or strikes with the hammer-end against one or the other of two bells placed at convenient distances and giving forth different musical tones. The alphabet of Steinheil, formed only of dots arranged in twodift'erentlines, presents the great ad vantage of being produced by currents of equal duration though of opposite directions. It is tobe remembered that Steinheil had in 1838discovered the possibility of using the earth instead of a second wire for the return of the current. "The oldest dial-instrument exhibited in the historical section was constructed in 1815 by Leonhard, in Berlin. In the receiver the current acts directly upon a needle, which turns gradually a ratchet-wheel fixed to its axis by means of an escapement, while in the transmitting-apparatus the circuit is broken and closed by means of wheels. "The next oldest instrument of the dial-system is that of Siemens, which was patented in Prussia in 1846 and exhibited at Paris in 1850. This telegraph, constructed upon a new principle, operates (as does the alarm joined to it) by automatic interruptions of the current. This is also the oldest printing-telegraph exhibited. It is furnished with an arrangement for making a dry impression of the desired letter by meaus of copying-paper u pou a moving...show more

Product details

  • Paperback | 252 pages
  • 189 x 246 x 13mm | 458g
  • Rarebooksclub.com
  • Miami Fl, United States
  • English
  • black & white illustrations
  • 1236671740
  • 9781236671745