• 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?

Fluoroscope

Clarence Madison Dally an employee of Thomas Edison at his West Orange research labs volunteered to work on the newly discovered x-rays. Using a fluoroscope, made of a fluoride gas filled light and two pieces of cardboard to focus the x-rays, Dally would expose himself to high concentrations of radiation eventually leading to radiation poisoning. After Dally’s death when Edison was asked about x-rays he would respond with “Don’t ask me about x-rays. I am afraid of them.”