From GHN

Revision as of 19:35, 30 December 2008 by Azalma (Talk | contribs)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

This article is a stub. You can help the GHN by expanding it.

Menlo Park, New Jersey. Using ideas he mentioned in a patent for telephony improvements filed on 30 July 1877 (the recording of sound by transverse indentations in a v-shaped groove in a paper tape or on a sheet of tinfoil wrapped on a cylinder), Edison drew a sketch for the phonograph on 29 November 1877 that was used to make a working model a few days later. The device was demonstrated to Scientific American on Dec. 7. Edison filed for a patent on Dec 15th. And the invention was announced publicly in Scientific American on Dec. 22nd.