Journal of the Society of Telegraph-Engineers and Electricians, Հատոր 12Published under the supervision of the Editing Comittee (London E and FN Spon), 1883 |
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Common terms and phrases
action ampères apparatus armature arrangement Ayrton battery bismuth brushes cable carbon cause cell centimètres charge circuit coil conductor connected constant copper current passing cylinder deflection diameter difference of potential direction discharge distance dynamo dynamo machine Earth Currents effect electrical resistance Electrician electro-magnet electro-motive force energy experiments field-magnet fixed gauze Gramme machine grammes heat horse-power increase induction induction balance instrument insulated lamps Leclanché cells lines of force London magnetic field magnetised means measure metal meter microphone molecular molecules motor Munro needle neutrality observations obtained ohms ordinary paper Phil placed plate points of contact polarisation polarity poles position Preece pressure produced Professor Hughes proportional resistance revolutions per minute rotation shown shunt Siemens Society soft iron speed spiral steel strength surface tangent galvanometer Telegraph telephone temperature theory torsion transmitter tube varying vibrations Vide volts weight Wheatstone bridge WILLOUGHBY SMITH
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Էջ 374 - ... such as magnetism and electricity. 3. That the inherent polarity or magnetism of each molecule is a constant quantity like gravity ; that it can neither be augmented nor destroyed. 4. That when we have external neutrality, or no apparent magnetism, the molecules or their polarities arrange themselves so as to satisfy their mutual attraction by the shortest path, and thus form a complete closed circuit of attrac tion.
Էջ 27 - I find a frank acknowledgment of one's ignorance is not only the easiest way to get rid of a difficulty, but the likeliest way to obtain information, and therefore I practise it ; I think it an honest policy.
Էջ 265 - The value of frequently testing the apparatus and circuits cannot be too strongly urged. The escape of electricity cannot be detected by the sense of smell, as can gas, but it can be detected by apparatus far more certain and delicate. Leakage not only means waste, but in the presence of moisture it means destruction of the conductor and its insulating covering, by electric action.
Էջ 94 - The force acting on the armature of an electro-magnet, in any position, is proportional to the square of the current ; (2) the square of the number of vibrations, say, of a pendulum, is a measure of the controlling force. Therefore, If the controlling force under which a body vibrates is due to the action of an electro-magnet on its armature, the square of the number of vibrations in a given time is a measure of the square of the electric current. In other words, the rate of vibrating is a measure...
Էջ 263 - The difficulties that beset the electrical engineer are chiefly internal and invisible, and they can only be effectually guarded against by " testing," or probing with electric currents. They depend chiefly on leakage, undue resistance in the conductor, and bad joints, which lead to waste of energy and the dangerous production of heat.
Էջ 372 - If we admit the assumption of electric currents around each molecule, the molecule itself would then be electromagnetic, and the question still remains, What is polarity ? Have the supposed electric currents separated the two assumed magnetic fluids contained in the molecule, as in Poisson's theory?
Էջ 251 - Letter to Captain Huish, as to proposed improvements in the Electric Telegraph System, for the service of the L.
Էջ 245 - I found that one ounce of lead was not sufficient on a surface of contact 1 centim. square to maintain constant^ contact ; and it was only by removing the musical box to a distance of several feet that I was enabled to preserve continuity of current with a moderate pressure. I have spoken to forty microphones at once ; and they all seemed to respond with equal force. Of course there must be a loss of energy in the conversion of molecular vibrations into electrical waves...
Էջ 372 - The whole of the magnetic molecular phenomena that we have been studying lead us to believe that the magnetization of a body is due to a particular arrangement of its molecules, originally endowed with magnetic virtue, but which in the natural state are so arranged that the magnetism of the body that they constitute is not apparent. Magnetism would, therefore, consist in disturbing this state of equilibrium, or in giving to the particles an arrangement that makes manifest the property with which...
Էջ 261 - Memoir on the difference between Leyden Discharges and Lightning Flashes, and on their relative action upon metallic bodies vicinal to the conductor of the respective discharges. 8vo. 42 pp. [Proc. London Electrical Soc., Dec.