Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 167,647 pages of information and 247,064 images on early companies, their products and the people who designed and built them.
Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 147,919 pages of information and 233,587 images on early companies, their products and the people who designed and built them.
Duo-Trac "Cell-o-Phone", a sound recorder that used cellophane tapes and an optical sound reproduction system.
1939 Demonstration of a new speech and music-reproduction system given on board a ship in the London Docks by International Marine Radio Co in collaboration with British Ozaphone, Ltd.
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