Note:  Do not rely on this information. It is very old.

Nautical Almanac

Nautical Almanac, an almanac issued under authority of the Board of Admiralty, under the direction of the "Nautical Almanac Office." It contains lists of the astronomical phenomena of the year, and the elements requisite for finding the longitude at sea. It first appeared in 1767 under the editorship of Dr. Maskelyne, then Astronomer-Royal, who superintended its preparation for forty years. The equivalent, French publication is called La Connaissance des Temps.