Journal, Volumen12

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Vols. 59-95, Dec. 1920-1948 include (1941-48, in pt. 3) Proceedings of the Radio section (as Wireless section, Chairman's address, 1920-40; as Wireless section, Proceedings, 1941-44).
 

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Página 578 - Explained, with numerous illustrations and Remarks. By JAMES SWINBURNE, late of JW Swan and Co., Paris, late of Brush-Swan Electric Light Company, USA i8mo, cloth, is. 6d. PhilippReis, Inventor of the Telephone: A Biographical Sketch.
Página 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.
Página 573 - Magnetical and Meteorological Observations, made at the Royal Observatory, Greenwich, in the year 1851, under the direction of George Biddell Airy, Esq.
Página 505 - ... from the heat of the sun or from the compression of the blocks, to a material loss of the preservative, or to thereby make a pitchy, dirty pavement, injurious to pedestrians, vehicles, floors and carpets of adjacent buildings, as occurs with tar products not creosote oils. Beyond giving several types it is unnecessary for me to go into the details of the several good wood preservatives and the laboratory tests of them, because their descriptions and tests are found in old, standard, open specifications...
Página 247 - I found that one ounce of lead was not sufficient on a surface of contact 1 centimetre 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, but it is so small that I...
Página 242 - I had made, the materials used, and the forms of microphone employed in demonstrating important points. I have made a great number of microphones, each for some special purpose, varying in form, mechanical arrangement, and materials. It would require too much time to describe even a few of them ; and as I am anxious in this paper to confine myself to general considerations, I will take it for granted that some of the forms of instrument and the results produced are already known. The problem which...
Página 246 - ... matter ; but as the best results as regards the human voice were obtained from two surfaces of solid gold, I am inclined to view with more favour the idea that an infinite variety of fresh contacts brought into play by •the molecular pressure affords the true explanation. It has the advantage of being supported by the numerous forms of microphone I have constructed, in all of which I can fully trace the effect. I have been very much struck by the great mechanical force exerted by this uprising...
Página 267 - 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.
Página 96 - The square of the number of vibrations, say, of a pendulum, is a measure of the controlling forceTherefore, 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 of the strength of the current, and the number of vibrations is a measure of its quantity. The exact form and nature of the...
Página 247 - ... 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 ; but it is so small that I have never been able to measure it with the simple appliances at my disposal. I have examined every portion of my room — wood, stone, metal, in fact all parts...

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