A journal for mariners and mathematician practitioners: The Nautical Almanac and astronomical ephemeris and the Board of Longitude (1767-1828)

International audienceThe “Nautical Almanac and Astronomical Ephemeris” was published from 1767 by Nevil Maskelyne via the Board of longitude, the commission instituted in 1714 by Queen Ann to solve the longitude problem on sea. The Almanac is an annually published ephemeris giving the positions of heavenly bodies for stated points in time and has provided essential data to navigators, geographers and astronomers. The tables also contained everything essential for a “general use” and its users had practically to be skilled on mathematical and even technical knowledge. This talk will consider the Almanac in relation with the Board of longitude and the strategies developed by Maskelyne to diffuse astronomical method in longitude computation. Keeping my attention on audiences, I’ll consider how, in 1828, the specialization of the Almanac asked by some of its audiences, i.e. mathematician practitioners or astronomers, eventually caused the dismantling of the Board of longitude