File:Detail showing liquid transmitter in Bell's U.S. Patent No. 161739 obtained in April, 1875.jpg
Jump to navigation
Jump to search
Detail_showing_liquid_transmitter_in_Bell's_U.S._Patent_No._161739_obtained_in_April,_1875.jpg (458 × 365 pixels, file size: 15 KB, MIME type: image/jpeg)