[Graphophone patents]

United States. Patent Office · 1878 · Washington, D.C., Govt. Print. Off. · 19 pictures

A collection of United States patent drawings issued by the Patent Office in Washington, D.C. in 1878, compiled as a record of early sound-recording inventions for patent examiners and engineers. The pictures are black-and-white mechanical line drawings of gears, levers, cylinders and frames with numbered reference callouts, useful to a designer as clear diagrams of early machine linkages and precise technical layouts.

Phonograph · Patents

Internet Archive · Smithsonian Libraries · Public domain (published before 1931) · More from this library