Electro-telegraphy

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E. & F.N. Spon, 1876 - Telegraph - 126 pages
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Page 36 - The strength of the current is directly proportional to the electro-motive force. b. The strength of the current is inversely proportional to the resistance. c. If the wire which unites the two poles of battery be of the same material, and of the same thickness throughout, the " electric fall " is the same throughout the wire.
Page 86 - Long strips or ribbons of paper are perforated, by a machine constructed for the purpose, with apertures grouped to represent the letters of the alphabet and other signs. A strip thus prepared is placed in an instrument, associated with a rheomotor (or source of electric power), which on being set in motion moves it along. and causes it to act on two pins in such manner that, when one of them is elevated, the current is transmitted to the telegraphic circuit in one direction, and when the other is...
Page 95 - This is a glass jar (fig. 53), with a coating of tinfoil pasted carefully inside and out, extending to within a few inches of the mouth. This last is generally closed by a wooden stopper, through which passes the stalk of a brass knob or ball, surmounting the whole. The connection between the inside coating and the ball is completed by a chain extending from the stalk to the bottom of the jar. If this jar be put on an...
Page 28 - The simplest form of cell consists of a plate of zinc and a plate of copper immersed in a vessel of dilute sulphuric acid, with copper wires attached to the plates. When the wires are joined the 'circuit is completed...
Page 86 - ... that when one of them is elevated, the current is transmitted to the telegraphic circuit in one direction, and when the other is elevated it is transmitted in the reverse direction. The elevations and depressions of these pins are governed by the apertures and intervening intervals. These currents, following each other indifferently in these two opposite directions, act upon a writing instrument at a distant station, in such a mauner as to produce corresponding marks on a slip of paper moved...
Page 86 - ... manner that when one of them is elevated the current is transmitted to the telegraphic circuit in one direction, and when the other is elevated it is transmitted in the reverse direction : the elevations and depressions of these pins are governed by the apertures and intervening intervals.

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