An account of the methods used to describe lines, on Dr. Halley's chart of the terraqueous globe ; shewing the variation of the magnetic needle about the year 1756, in all the known seas ; their application and use in correcting the longitude at sea ; with some occasional observations relating thereto / [William Mountaine].

Licence: Public Domain Mark

Credit: An account of the methods used to describe lines, on Dr. Halley's chart of the terraqueous globe ; shewing the variation of the magnetic needle about the year 1756, in all the known seas ; their application and use in correcting the longitude at sea ; with some occasional observations relating thereto / [William Mountaine]. Source: Wellcome Collection.