"Rarified Air"

[phonogfp]

“On This Day in the History of Recorded Sound…”

March 17, 1892: Leon F. Douglass filed for a U.S. patent for “Method of and Means for Duplicating or Transferring Phonographic Records.” This involved simply attaching the reproducer of one phonograph to the recorder of another phonograph with a squeezed rubber tube, resulting in a partial vacuum (“rarified air”).

https://www.antiquephono.org/#/