Book Id: 40778 Autograph letter signed to C. Becker. Willoughby Smith.

Autograph letter signed to C. Becker.

Publisher Information: 1870.

Smith, Willoughby (1828-91). A.L.s. to C. Becker. London, January 24, 1870. 1 page. 201 x 127 mm. Remains of mounting present. Provenance: Latimer Clark.

From Willoughby Smith, chief electrician for the Telegraph Construction and Maintenance Company, and discoverer of selenium's light-sensitive properties, regarding an order for "six marine, six astatic and six speaking galvanometers." As an engineer with the Gutta-Percha Company of London, Smith helped to manufacture and lay the first undersea cables in the English Channel and the Mediterranean; he also worked on the 1858, 1865, and 1866 Atlantic cables. In 1873 Smith discovered that metallic selenium is electrically sensitive to light, and that its electrical conductivity varies in proportion to the amount of exposure to light. This discovery provided a stimulus to inventors interested in "phototelegraphy," or the transmission of optical images over distances by electricity, and is considered a key development in the origins of television. Origins of Cyberspace 199.

Very Good. Book Id: 40778

Price: $500.00

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