American Telegraphy and Encyclopedia of the Telegraph: Systems, Apparatus, Operation, Embracing Electrical Testing; Primary and Storage Batteries; Dynamo Machines; Morse Duplex, Quadruplex, Multiplex, Submarine, Automatic, and Wireless Telegraphy; Burglar-alarm, Fire-alarm, and Police-alarm Telegraphy; Printing Telegraphy; Military and Naval Signaling; Railway Block Systems; Telegraph Wires, Cables, and Conduits; Etc |
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American Telegraphy and Encyclopedia of the Telegraph: Systems, Apparatus ... William Maver, Jr. No preview available - 2015 |
Common terms and phrases
adjusted ampere apparatus armature lever arrangement artificial line automatic binding posts break-wheel cable capacity caused cell central office circuit closed coil condenser conductor connected contact points core current strength cylinder deflection depressed device disc dots duplex dynamo dynamo machine electric electro-magnet electromotive force employed figure galvanometer ground inch indicated inductance induction coil instrument insulated iron letter line wire lines of force local battery loop magnet main line metal mile Morse needle neutral relay normally Ohm's law ohms operation oscillations paper passes perforated placed plate polarized relay pole pole-changer position potential practically printer pulsations quadruplex receiving repeating result reversals rheostat rotation screw segments semaphore shaft short-circuited shown in Fig shunt side signal box siphon recorder sounder strength of current strip switch tangent galvanometer telegraph system telephone terminal terminal stations thereby ticker transmitter type-wheel vibration volts Wheatstone Wheatstone bridge wheel zinc
Popular passages
Page 366 - Each motion will embrace an arc of 90°, starting from and returning to the vertical. The long dash (letter " L " and numeral " naught ") is distinguished from the " T " dash by A slight pause at the lowest point of dip, and with this exception there will be no pause whatever between the motions required for any single letter. A slight pause will be made between letters. At the end of each word, abbreviation, or conventional signal the space signal, or /"front '' motion, is made, preceded and followed...
Page 325 - When the system is in operation the beam or pencil of light is moved to the right or left, depending on the direction of the current...
Page 366 - If the receiver sees that the sender's mirror or light needs adjustment, he will turn on a steady flash until answered by a steady flash. When the adjustment is satisfactory the receiver will cut off his flash and the sender will resume his message.
Page 335 - When electric waves are set up in the neighborhood of this circuit, electromotive forces are generated in it which appear to bring the filings more closely together, that is, to cohere, and thus their electrical resistance decreases, from which cause this piece of apparatus — the tube and its filings — is termed a "coherer.
Page 436 - It may also be noted in this relation that quite a high degree of skill is required on the part of the operator of the Phelps and similar keyboards to secure the best results.
Page 94 - The total resistance of a parallel circuit is equal to the reciprocal of the sum of the reciprocals of the individual resistances of the circuit.
Page 6 - Ohm's law may therefore be expressed by the following equation: 1= * ~R where /is the current in amperes, E the electromotive force in volts and R the resistance in ohms. It is therefore evident, that if the electromotive force and...
Page 335 - ... or receiver, when they fall upon it. The manner in which Professor Hertz proceeded to show the existence of electric, waves in free space was, briefly, as follows: It was already known that electric oscillations could be set up in a wellinsulated wire or conductor; in fact, that the discharge of the Leyden jar is made up of a series of electric oscillations, as had been shown by Lord Kelvin in 1853. Hertz set up electric oscillations by means of ¡m electric oscillator, shown in tig.
Page 156 - R' and its lever /' falls back, as in the figure, and opens the local circuit controlling the transmitter T'. As the latter instrument opens, it first breaks the local circuit of EM at a' ; the retractile spring s of extra magnet EM, at once pulls its lever against the lever /of relay R as in figure; presently the transmitter T...
Page 181 - ... north pole of one magnet will attract the south pole of another, and the south pole of one will attract the north of another ; but the north...