Original linen-backed patent lithograph for the Magnavox Company's invention of a loud speaker, one page, 12.5 x 10.25, June 30, 1932. The diagram features multiple views of the speaker, which employs a conical diaphragm powered by an actuating coil. The top border reads: "375,538 Complete Specification." The lower border features the printed text: "Charles & Read Ltd. Photo-Litho." The left border reads: "This Drawing is a reproduction of the Original on a reduced scale." Includes the printed British "Patent Specification" document, four pages on two sheets, which describes the invention as "a novel construction for sound reproducing apparatus which will greatly simplify and reduce the cost of assembling." The specification sheet bears a "U.S. Patent Office Library" ink stamp on the first page. In fine condition.
