Ueber telephonie

Publisher Information: Frankfurt: 1861.

Reis, Johann Philipp (1834-74). Ueber Telephonie durch den galvanischen Strom. In Jahres-Bericht des physikalischen Vereins zu Frankfurt am Main fur das Rechnungsjahr 1860-1861 (1861): 57-64. Text illustrations; 3 folding plates (nos. I-III). Whole number, 8vo. 80pp. 5 folding plates/charts. 221 x 142 mm. Without wrappers. First and last few leaves lightly foxed, corners a bit frayed, but very good. Boxed.

Book Id: 38692

First Edition. Reis, a German schoolteacher and physicist, began experimenting with the electrical transmission of sound in the late 1850s, and by 1861 had designed several transmitters and receivers.

"In Reis's instruments, a contact in an electrical circuit was established between a metal point and a metal strip resting on a membrane in the transmitter. It was Reis's theory that, as the membrane vibrated, the metal point would bounce up and down, producing intermittent contact and intermittent current synchronous with the vibrations, and that, furthermore, the height of the bounce, the force of its return, and the amplitude of the current pulse would vary with the intensity of the sound. Thus, he expected that something of the quality as well as the intensity of the sound would be conveyed" (internet reference).

As the above quotation indicates, Reis believed that interrupted contact between transmitter and electrical circuit was essential to the reproduction of sound. However, the reproduction of speech in fact requires continuous contact and an undulating current; thus Reis's instruments, although capable of transmitting musical tones and certain other sounds, could not reliably transmit intelligible speech. Reis built several examples of his device and authorized its reproduction, but did not attempt to patent it or develop it further. Invention of the first successful speaking telephone was not achieved until the 1870s, when Bell, Edison and Elisha Gray each patented their own instruments.

Reis announced his invention in a lecture delivered before the Physical Society of Frankfurt on October 26, 1861, and published his first printed account of the device in the Society's annual Jahresbericht for 1860-61. The membership list printed on pp. 3-5 of this issue shows the Society numbering around 100 members, and it is reasonable to assume that the edition of the 1860-61 Jahresbericht was correspondingly small. Wheeler Gift 1532.

.

Price: $5,000.00

See all items by