Go back to article: A tale of two telegraphs: Cooke and Wheatstone’s differing visions of electric telegraphy
© Trustees of the Science Museum Group/Science & Society Picture Library
Charles Wheatstone’s ABC instrument, based on the 1860 specification (Patent No. 2462) and further improved c. 1865. It combined the Communicator and Indicator into a single instrument, together with a magneto-electric generator to avoid battery operation. This instrument is stamped ‘General Post Office’.