Ørsted's [Oersted] apparatus for showing the effect of an electric current on a magnetic needle, believed to have been supplied for £1-8-0 by Watkins and Hill, Charing Cross, Westminster, 1828.
Hans Christian Oersted was a Danish physicist and chemist who in 1820 discovered the relationship between electricity and magnetism. He found that a magnetised needle moved when brought near a wire in which current was flowing, and that the effect was increased if the wire was formed into a coil. The idea of using this phenomenon as a signalling system soon occurred to several experimenters. This instrument is believed to have been used at lecture demonstrations in London.