A Manual of Telephony |
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Common terms and phrases
actuated adjustable alternating currents apparatus armature arrangement battery Bell instrument brass British Patent Specification cable call-bell call-wire carbon block carbon disc carbon pencils centre clamped conductor connected copper wire cylinder diameter diaphragm direct disconnected DISTRIBUTING BOARD earth ebonite effect electrical resistance electro-magnet Elisha Gray exchange fitted fixed flexible cord front galvanometer holes inches induction coil instrument insulated intermediate iron joined Leclanché cells lever magnetic field means metallic circuits microphone mouthpiece multiple switch ohms operator operator's ordinary pair of pegs pendulum permanent current permanent magnet placed plate platinum pole Post Office press-button primary wire receiver relay renters resistance ring-off indicator RINGING KEYS screw secondary wire short-circuit shown in fig side single-wire soft-iron sonorous vibrations speaking spring station strip sub-trunk subscriber's subscribers switch-hole switch-springs switchboard table-key telegraph telephone terminal test-board tion transmitter trembler bell tube upper variations vertical vibrations
Popular passages
Page 4 - Watson, at the far end of the line, holding his mouth close to a stretched membrane, such as you see before you here, carrying a little piece of soft iron, which was thus made to perform in the neighborhood of an electro-magnet in circuit with the line motions proportional to the sonorific motions of the air.
Page 4 - In the Canadian department I heard 'To be or not to be, . . . there's the rub,' through an electric telegraph wire; but, scorning monosyllables, the electric articulation rose to higher flights, and gave me passages taken at random from the New York newspapers: — 'SS Cox has arrived' (I failed to make out the SS Cox) ; 'The City of New York...
Page 4 - This, the greatest by far of all the marvels of the electric telegraph, is due to a young countryman of our own, Mr. Graham Bell, of Edinburgh and Montreal and Boston, now becoming a naturalised citizen of the United States.
Page 2 - Suppose that a man speaks near a movable disk sufficiently pliable to lose none of the vibrations of the voice, and that this disk alternately makes and breaks the current from a battery; you may have at a distance another disk which will simultaneously execute the same vibrations.
Page 2 - It is certain that in a more or less distant future speech will be transmitted by electricity.
Page 445 - The twist-test will be made as follows: The wire will be gripped by two vises, one of which will be made to revolve at a speed not exceeding one revolution per second. The twists thus given to the wire will be reckoned by means of an ink mark which forms a spiral on the wire during torsion, the full number of twists to be visible between the vises.
Page 4 - Who can but admire the hardihood of invention which devised such very slight means to realize the mathematical conception that, if electricity is to convey all the delicacies of quality which distinguish articulate speech, the strength of its current must vary continuously, as nearly as may be, in simple proportion to the velocity of a particle of air engaged in constituting the sounds.
Page 2 - Incited thereto by my lessons in physics in the year 1860, I attacked a work begun much earlier concerning the organs of hearing, and soon had the joy to see my pains rewarded with success, since I succeeded in inventing an apparatus by which it is possible to make clear and evident the functions of the organs of hearing, but in which also one can produce tones of all kinds at 1 v. Guillemin, " Le Monde Physique,
Page 4 - All this my own ears heard spoken to me with unmistakable distinctness by the thin circular disc armature of just such another little electromagnet as this which I hold in my hand.
Page 445 - Tests for tensile strength may be made with a lever or other . machine which has the approval of the officer appointed on behalf of the Postmaster-General to inspect the wire, and hereinafter called the Inspecting Officer, who shall be afforded all requisite facilities for proving the correctness of the machine. (6) The electrical resistance of each test-piece shall be reduced according to its diameter, and shall be calculated for a temperature of 60° Fahr. Such test-piece shall measure not less...