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 Summary
       
        
         | Description | 
         
           Photo of wax cylinder recording medium in  Dictaphone  dictating machine from the 1920s. The recording head at right moves from left to right. To play it back, 'stethoscope' type earphones are plugged into the hole in the recording head. The dark bands are shiny gaps between recordings, made by moving the needle forward before each dictation, enabling the typist to find the specific track needed. Each wax cylinder can record 1200-1500 words, and can be reused 100-120 times by putting it in an erasing machine that 'shaves' off the surface.  | 
        
        
         | Source | 
         
           Downloaded on 2008-1-12 from  Clarence Charles Smith (1922) The Expert Typist, MacMillan Co., New York, USA, p.125, fig.40 on Google Books. The photo is credited (p.122) to the Columbia Phonograph Co.  | 
        
        
         | Date | 
         
           1922  | 
        
        
         | Author | 
         
           Colombia Phonograph Co.  | 
        
        
         Permission ( Reusing this image) | 
         
           Public domain - published in USA before 1923. 
            
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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, 1923. 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 Canada, China (not Hong Kong, Macao, or Taiwan Area), 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 | 
        Dimensions | 
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        | current | 
         13:06, 12 January 2008 | 
        789×453 (103 KB) | 
        Chetvorno | 
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