Go back to article: A tale of two telegraphs: Cooke and Wheatstone’s differing visions of electric telegraphy

Figure 4

Colour photograph of Charles Wheatstone’s ABC instrument from 1860 which combined the Communicator and Indicator into a single instrument. This instrument is stamped General Post Office

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’.