The Story of Wireless TelegraphyD. Appleton, 1904 - 207 էջ |
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aerial telegraphy APPLETON AND COMPANY battery boat cable Carlo Alberta coherer communication condenser conduction connected copper wire detector diameter discharge discovery distance Dolbear earth earth-plates effect elec electric waves electromagnetic waves etheric wave exciter experiments feet Flat Holm galvanometer graphy ground Hertz induction coil instrument insulated interrupter invention inventor investigations kilometers Lavernock Point length Leyden jar light lighthouse magnetic Mahlon Loomis Marconi mast means ments mercury messages metal plates meters method microphone miles Morse key needle obtained oscillations patent Poldhu poles possible practical Preece's primary circuit receiving apparatus regard relay resistance sending station sensitive ship shore shown in Fig signals Sir Oliver Lodge Sir William space spark-gap sparks Steep Holm successful surface syntony tance telephone terminal tion transmission transmitting tricity Trowbridge tube vertical conductor vertical wire vessel William Preece Wimereux wireless tele wireless telegraphy yards
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Էջ 108 - Here is unfolded to us a new and astonishing world — one which it is hard to conceive should contain no possibilities of transmitting and receiving intelligence. Rays of light will not pierce through a wall, nor, as we know only too well, through a London fog. But the electrical vibrations of a yard or more in wave-length of which I have spoken will easily pierce such mediums, which to them will be transparent.
Էջ 105 - ... handy they will run along it, and may be felt a long way off. If no wire exists they will spread out like sound from a bell, or light from a spark, and their intensity will decrease according to the inverse square of the distance. Maxwell and his followers well knew that there would be such waves ; they knew the rate at which they would go, they knew that they would go slower in glass and water than in air, they knew that they would curl round sharp edges, that they would be partly absorbed but...
Էջ 117 - I was so discouraged at being unable to convince them of the truth of these aerial electric waves that I actually refused to write a paper on the subject until I was better prepared to demonstrate the existence of these waves ; and I continued my experiments for some years, in hopes of arriving at a perfect scientific demonstration of the existence of aerial electric waves produced by a spark from the extra currents in coils, or from frictional electricity, or from secondary coils.
Էջ 111 - This is no mere dream of a visionary philosopher. All the requisites needed to bring it within the grasp of daily life are well within the possibilities of discovery, and are so reasonable and so clearly in the path of researches which are now being actively prosecuted in every capital of Europe, that we may any day expect to hear that they have emerged from the realms of speculation into those of sober fact.