Scientist, Fellow of the Royal Society, and first principal librarian of the of the British Museum (1756-72).

Franklin admired his work on magnetism, and forwarded a copy of his treatise, An Attempt to demonstrate that all the Phenomena in Nature may be explained by … Attraction and Repulsion (London, 1748), to Ezra Stiles in 1755.

Invented a mariner’s compass that eventually became the standard compass for the royal navy.