Tabulating the heavens: Computing the Nautical Almanac in 18th-Century England

Abstract

The question of how to accurately find longitude at sea was hotly debated in the mid-1700s. This article describes the lunar distance method, promoted by Nevil Maskelyne, the British Astronomer Royal. In 1767, Maskelyne began publishing the Nautical Almanac, which contained astronomical tables prepared by a small network of human computers during the period 1765-1809. This article will describe the computing system Maskelyne created to compute the necessary tables.