United States. Patent Office · Washington, D.C., Govt. Print. Off. · leaf 378
honograph diaphragm composed of a sheet of glass and a sheet of non-vitreous ma-terial in close contact with each other. 6. A phonograph diaphragm composed of asheet of glass and a sheet of metal connectedtogether. In testimony whereof I hereunto set myhand, this 31st day of October, 1891, in… … j^^^,
Phonograph · Patents
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