Electric telegraph, 18th October 1838.
© Science Museum / Science & Society Picture Library
One of six line drawings with colour wash by J Farey, of William Fothergill Cook's (1806-1879) specification for 'Improvements in giving signals and sounding alarums at distant places by means of Electric Currents transmitted through metallic Circuits'. This is Sheet A of the Second English specification. The patent was sealed 18 April 1838.