Edward Samuel Ritchie (1814–1895), an American inventor and physicist, is considered to be the most innovative instrument maker in nineteenth-century America, making important contributions to both science and navigation.
[2] In the early 1850s, after examining an example of an electric induction coil made by German instrument maker Heinrich Daniel Ruhmkorff, which produced a small two-inch (50 mm) electric spark when energized, Ritchie perceived that it could be made more efficient and produce a longer spark by redesigning and improving its secondary insulation.
[3][4][5] In 1857, one of Ritchie's induction coils was exhibited in Dublin, Ireland at a conference of the British Association for the Advancement of Science,[6] and later at the University of Edinburgh in Scotland.
At the time, British Admiralty dry-mount nautical compasses were considered by all navies and merchant shipping companies as the technological standard of the day.
[12] With the damping provided by the liquid, together with a gimbal mounting, the floating indicator or card of the Ritchie compass remained relatively stable even when a ship's deck pitched and rolled during periods of severe weather.