 from Edison NHS |
 from NMAH Acoustic Devices |
 from NMAH Acoustic devices |
|
from Edison NHS |
from NMAH Acoustic Devices |
from NMAH Acoustic devices |
| Edison's first phonograph of 1877 recorded sound by "indenting" or making up-and-down impressions in a groove cut into a thin surface of tin foil on a metal cylinder 4 inches long, 100 grooves per inch, powered by a hand crank at a speed of about 70 rpm. | Tainter & Bell's graphophone of 1885 recorded sound by "incising" or making a vertical "hill-and-dale" cut in a thin surface of beeswax on a cardboard tube 6 inches long and 1-5/16 inches wide, 160 grooves per inch, powered by a hand crank at a speed of about 80 rpm, after 1887 by a foot treadle at 120 rpm. | Berliner's gramophone of 1888 recorded sound by "undulation" or making a wavy side-to-side lateral cut in a thin wax surface that was etched by acid on one side of a flat zinc disc about 7 inches in diameter and used to press hard rubber copies, powered by a hand crank at a speed of about 30 rpm for the May 16 demonstration at the Franklin Institute, increased later to 60 rpm. |