Wireless: From Marconi's Black-box to the Audion

Cover
MIT Press, 2001 - 248 Seiten

By 1897 Guglielmo Marconi had transformed James Clerk Maxwell's theory of electromagnetic waves into a workable wireless telegraphy system, and by 1907 Lee de Forest had invented the Audion, a feedback amplifier and oscillator that opened the way to practical radio transmission. Fifteen years after Marconi's invention, wireless had become an essential means of communication, as well as a hobby for many.

This book offers a new perspective on the early days of wireless communication. Drawing on previously untapped archival evidence and recent work in the history and sociology of science and technology, it examines the substance and context of both experimental and theoretical aspects of engineering and scientific practices in the first years of this technology. It offers new insights into the relationship between Marconi and his scientific advisor, the physicist John Ambrose Fleming (inventor of the vacuum tube). It includes the full story of the infamous 1903 incident in which Marconi's opponent Nevil Maskelyne interfered with Fleming's public demonstration of Marconi's syntonic (tuning) system at the Royal Institution by sending derogatory messages from his own transmitter. The analysis of the Maskelyne affair highlights the struggle between Marconi and his opponents, the efficacy of early syntonic devices, Fleming's role as a public witness to Marconi's private experiments, and the nature of Marconi's "shows." It also provides a rare case study of how the credibility of an engineer can be created, consumed, and suddenly destroyed. The book concludes with a discussion of de Forest's Audion and the shift from wireless telegraphy to radio.

 

Inhalt

Hertzian Optics and Wireless Telegraphy
1
Inventing the Invention of Wireless Telegraphy Marconi versus Lodge
25
Grafting Power Technology onto Wireless Telegraphy Marconi and Fleming on Transatlantic Signaling
53
Tuning Jamming and the Maskelyne Affair
89
Transforming an Effect into an Artifact The Thermionic Valve
119
The Audion and the Continuous Wave
155
The Making of the Radio Age
191
Electron Theory and the Good Earth in Wireless Telegraphy
193
Notes
199
Bibliography
229
Index
245
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Seite 12 - ... guttapercha coverings and iron sheathings will be relegated to the Museum of Antiquities. Then, when a person wants to telegraph to a friend, he knows not where, he will call in an electromagnetic voice, which will be heard loud by him who has the electromagnetic ear, but will be silent to everyone else. He will call, "Where are you?" and the reply will come, "I am at the bottom of the coal mine
Seite 9 - 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 . . . will easily pierce such mediums, which to them will be transparent. Here, then, is revealed the bewildering possibility of telegraphy without wires, posts, cables, or any of our present costly appliances.
Seite 11 - ... 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. Even now, indeed, telegraphing without wires is possible within a restricted radius of a few hundred yards, and some years ago I assisted at experiments where messages were transmitted from one part...
Seite 10 - ... of a few feet in length, which will easily pass through buildings and fogs, to those long waves whose lengths are measured by tens, hundreds, and thousands of miles; secondly, more delicate receivers which will respond to wavelengths between certain defined limits and be silent to all others; thirdly, means of darting the sheaf of rays in any desired direction, whether by lenses or reflectors, by the help of which the sensitiveness of the receiver...
Seite 40 - He has not discovered any new rays ; his transmitter is comparatively old ; his receiver is based on Branly's coherer. Columbus did not invent the egg, but he showed how to make it stand on its end, and Marconi has produced from known means a new electric eye, more delicate than any known electrical instrument, and a new system of telegraphy that will reach places hitherto inaccessible.
Seite 10 - Also an experimentalist at a distance can receive some, if not all, of these rays on a properly constituted instrument, and by concerted signals messages in the Morse code can thus pass from one operator to another...
Seite 10 - Any two friends living within the radius of sensibility of their receiving instruments, having first decided on their special wave.length and attuned their respective instruments to mutual receptivity, could thus communicate as long and as often as they pleased by timing the impulses to produce long and short intervals on the ordinary Morse code.
Seite 139 - It is only by the possession of such an instrument" he said, "that we can hope to study properly the sending powers of various transmitters, or the efficiency of different forms of aerial, or devices by which the wave is...
Seite 145 - Hence we see that the insulation of electricity in "vacuum" is to be explained, not by any resistance of vacant space or of ether, but by a resistance of glass or metal or other solid or liquid against the extraction of electrions from it, or against the tearing away of electrified fragments of its own substance. The kathode torrent of resinously electrified particles, discovered in * By " vacuum " I mean space occupied only by the luminiferous ether, t Sir William Thomson's Electrostatics and Magnetism,...
Seite 11 - There is no doubt that the day will come, maybe when you and I are forgotten, when copper wires, gutta-percha coverings and iron sheathings will be relegated to the Museum of Antiquities. Then, when a person wants to telegraph to a friend, he knows not where, he will call in an electromagnetic voice, which will be heard loud by him who has the electro-magnetic ear, but will be silent to everyone else. He will call 'Where are you?' and the reply will come 'I am at the bottom of the coal-mine

Autoren-Profil (2001)

Sungook Hong is Associate Professor at the Institute for the History and Philosophy of Science and Technology at the University of Toronto.

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