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Lot 25

A Rare Pair of Romer's Acoustic Switches,
German, circa 1903,
(2)

25 February 2004, 14:00 GMT
London, Knightsbridge

Sold for £470 inc. premium

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A Rare Pair of Romer's Acoustic Switches, German, circa 1903,

made by Eduard Zimmermann, each with diaphragm connected to a solenoid and saucer bell, on cast iron tripod stand 17 in. (43 cm.) high (2)

Footnotes

These types of acoustic switches were used in experiments on psychiatric patients. The diaphragm is moved by the air pressure of a vocal sound which is amplified by the solenoid and indicated by the ringing of the bell.
The apparatus is illustrated in the price list and catalogue of Zimmermann instruments, published Leipzig, 1903.

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