• Heavy Machine Shop

    Thomas Edison

    National Historical Park New Jersey

Talking Doll Record: Hear the Audio

 
The record groove surface viewed under a microscope.

The record groove surface viewed under a microscope.  The nearly uniform groove width shows Edison's early square "chisel-cut" recording technique, used prior to August 1889. 

National Park Service

Specifications of the tin cylinder phonograph record:

  • Estimated original outer diameter (if not misshaped): ~60.4 mm (~2-3/8 inch)
  • Estimated original inner diameter (if not misshaped): ~53.7 mm (~2-1/8 inch)
  • Width: ~ 11.4 mm (~7/16 inch)
  • Thickness: ~ 3.4 mm (~1/8 inch)
  • Groove threads per inch: 50
  • Groove type: Vertical cut, nearly uniform groove width.
  • Recording/playback speed: Unknown. (The playback speed/pitch of the recording as presented here was set by ear.)

Return to "Early Talking Doll Recording Discovered" page.

Did You Know?

Photograph of Thomas Edison at the age of fourteen years.

There is a rumor that Edison was actually born in Mexico, based on his middle name Alva. However, Alva was the name of a family friend, Captain Bradley. When he was young, Edison's nickname was "Al," from his middle name Alva.