Note on a Magnetic Detector of Electric Waves

Guglielmo MARCONI

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Item#: 120951 price:$950.00

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MARCONI, Guglielmo. "Note on a Magnetic Detector of Electric Waves, Which Can Be Employed as a Receiver for Space Telegraphy" and "A Note on the Effect of Daylight upon the Propagation of Electromagnetic Impulses over Long Distances." IN: Proceedings of the Royal Society, Volume LXX, Number 463, pp. 341-347. [London]: (Harrison and Sons), July 29, 1902. Slim octavo, original taupe paper wrappers. Housed in a custom clamshell box. $950.

First edition of the first publication of two of Marconi’s most important papers on the long-distance transmission of signals and telegraphy.

In "Notes on a Magnetic Detector," Marconi described his invention of a magnetic conductor with uniform and constant resistance that works at much lower electromotive force. Upon experimentation, he discovered that "jerks in the magnetic condition" of the iron would allow induced strong enough currents in a coil of wire to allow the signal to be transmitted intelligibly on a telephone. The reception was then improved by the addition of tuning coils to the receiver so that its aerial only passed on oscillations identical to the ones originally transmitted. In his second paper, "A Note on the Effect of Daylight," Marconi noted marked differences in the distances at which it was possible to detect signal oscillations in the day versus at night. With the transmitter located in Podhu, England and the receiving station on board the U.S.S. Philadelphia to allow for mobility, Marconi found that there were no differences between day and night signals within a distance of 500 miles, but that, at distances greater than 700 miles, the signals transmitted during the day failed, while those at night were easily detected. Both of these papers signaled rapid progress in the field of telegraphy and paved the way for future advancements in telecommunications. Marconi was co-awarded the Nobel Prize with K.F. Braun in 1909 "for contributions to the development of wireless telegraphy." With index slip laid in. DSB IX:99.

A bit of creasing to spine, minor toning to fore-edge of front wrapper. About-fine condition.

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