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In 1826, Poggendorff developed the mirror galvanometer, a device for detecting electric currents. He had an extraordinary memory, well stored with scientific knowledge, both modern and historical, a cool and impartial judgment, and a strong preference for facts as against theory of the speculative kind.
A mirror galvanometer is an ammeter that indicates it has sensed an electric current by deflecting a light beam with a mirror. The beam of light projected on a scale acts as a long massless pointer. In 1826, Johann Christian Poggendorff developed the mirror galvanometer for detecting electric currents. The apparatus is also known as a spot ...
An early mirror galvanometer was invented in 1826 by Johann Christian Poggendorff. [citation needed] An astatic galvanometer was invented by Hermann von Helmholtz in 1849; a more sensitive version of that device, the Thomson mirror galvanometer, was patented in 1858 by William Thomson (Lord Kelvin). [3]
Mirror galvanometer by James W. Queen & Company Cascade above the Basin, Franconia Mountains, N.H, by James W. Queen & Company. James W. Queen & Company was an optical and scientific instrument company located at 924 Chestnut Street, Philadelphia, Pennsylvania, with a branch office in New York City, and active in various forms from 1853 to 1925, and subsequently as Gray Instrument Company ...
The mirror galvanometer proved yet another point of contention. Whitehouse wanted to work the cable with a very different scheme, [ 43 ] driving it with a massive high-voltage induction coil producing several thousand volts, so enough current would be available to drive standard electromechanical printing telegraphs used on inland telegraphs ...
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Printable version; In other projects ... Early Geiger counter, made by Hans Geiger, 1932. ... Thomson's mirror galvanometer, 1858.