The Electro Magnetic Telegraph; With an Historical Account of Its Rise, Progress, and Present Condition

The Electro Magnetic Telegraph; With an Historical Account of Its Rise, Progress, and Present Condition

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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. 1853 edition. Excerpt: ...opposite electro-magnet (in the instrument) is in connection, and thereby throw the battery into said circuit."--Journ. Frank. Inst. vol. xxi. 3d series. The object of this repeater is for the purpose of repeating or recording a communication in several places at once along a line, and at the same time allowing the galvanic circuit to remain open when the line is not in use. Siemenss Improvements in Electric Telegraphs.--Ernst Werner Siemens, of Berlin, patented in England, April 23, 1850, the following improvements.--Claims: "1st. The constructing electro-magnets for telegraphic purposes, of longitudinally divided tubes of iron or other magnetic metal, or of bundles of wire of iron or other magnetic metal. "2d. The construction of instruments for obtaining motion for telegraphic purposes, by means of one or two electro-magnets revolving on their axes within the fixed coils, by which they are rendered magnetic, or mounted on a transverse axis, and vibrating from side to side within the coils, by which they are magnetized. "3d. The construction of instruments for producing motion for telegraphic purposes by means of metallic spiral coils or bands traversed by electric currents, and attracting or repelling each other; also producing motion in such spirals by the proximity of permanent magnets, which at the same time serve to produce electric currents by induction for working telegraphic apparatus. "4th. The construction of the conducting contact pieces of alloys of platinum, iridium, or palladium with gold or silver, whether such alloys be farther alloyed by the admixture of other metals or not. "5th. The construction of electric telegraphic printing apparatus in such manner that the magnet, which works the step by...show more

Product details

  • Paperback | 120 pages
  • 189 x 246 x 6mm | 227g
  • Rarebooksclub.com
  • Miami Fl, United States
  • English
  • black & white illustrations
  • 1236536762
  • 9781236536761