Image: Wax cylinder in Dictaphone

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.
Title: Wax cylinder in Dictaphone
Credit: 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.
Author: Colombia Phonograph Co.
Permission: Public domain - published in USA before 1923.
Usage Terms: Public domain
License: Public domain
Attribution Required?: No