File:Bells first wall telephone 1877.jpg
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Summary[edit]
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English: The first Bell wall telephone, designed by Alexander Graham Bell in August 1877as a wall version of his "box" telephone. It contained a dynamic moving-iron driver that could be used as either a transmitter (microphone) or receiver (earphone) although is was mostly used as a transmitter with a separate earpiece receiver. It was constructed similarly to Bell's "box" telephone, with a horseshoe magnet with coils wound around the two poles near a sheet iron diaphragm. The difference was the pole pieces, diaphragm and mouthpiece horn were placed at right angles to the magnet. Caption: The first commercial wall telephone |
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| Source | Retrieved October 25, 2014 from C. E. Scribner, "The Creation of the Telephone" in Telephony magazine, Telephony Publishing Co., Chicago, Vol. 73, No. 12, September 22, 1917, p. 27, fig. 10 on Google Books |
| Author | C. E. Scribner |
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This media file is in the public domain in the United States. This applies to U.S. works where the copyright has expired, often because its first publication occurred prior to January 1, 1929, and if not then due to lack of notice or renewal. See this page for further explanation.
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This image might not be in the public domain outside of the United States; this especially applies in the countries and areas that do not apply the rule of the shorter term for US works, such as Canada, Mainland China (not Hong Kong or Macao), Germany, Mexico, and Switzerland. The creator and year of publication are essential information and must be provided. See Wikipedia:Public domain and Wikipedia:Copyrights for more details.
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| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 00:50, 27 October 2014 | | 406 × 710 (39 KB) | Chetvorno (talk | contribs) | User created page with UploadWizard |
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- File:Bell box wall telephone 1877.jpg (file redirect)
