Lunar Observations

Lunar Observations, or the Lun ae Method, a way of observing the angular distance between the moon and the sun or a fixed star, and comparing it with the computed distance in the Nautical Ephemeris, for the purpose of ascertaining the longitude at sea. The method, a very ancient one, was readopted and perfected by Dr. Nevil Maskelyne when on a mission to observe the transit of Venus in 1761; and it was Dr. Maskelyne who first proposed and superintended the preparation of the Nautical Almanac, the tables in which relieve the calculator from all the more laborious part of the process.