In the “Correspondence” section of your December 1985 issue, there is a letter about Edison’s phonograph. It is not remembered generally that Edison invented the phonograph not for the playback of music but primarily for the transcription of dictation. His first announcement of this apparatus in 1878 declared: “The apparatus now being perfected in mechanical details will be the standard phonograph.… The main utility of the phonograph, however, being for the purpose of letter-writing and other forms of dictation, the design is made with a view to its utility for that purpose.” Gen. Benjamin F. Butler wrote to the inventor about this; Edison replied on February 19, 1878: “I shall probably come to Washington in a few days with the Phonograph. … It talks clear and distinct, and I will give one of your stenographers a chance to take down 500 clearly articulated words in a minute.”
Edison’s letter to Butler is contained in the Butler repository of 377 manuscript boxes now in the Library of Congress.