Patent Information
Publication number: US200521 A
Patent Title: Improvement in phonograph or speaking machines
Publication type: Grant
Publication date: Feb 19, 1878
Filing date: Dec 24, 1877
Patent Information
Publication number: US200521 A
Patent Title: Improvement in phonograph or speaking machines
Publication type: Grant
Publication date: Feb 19, 1878
Filing date: Dec 24, 1877