Authorized by Congress in 1849, the American Nautical Almanac Office was founded and attached to the
Department of the Navy with
Charles Henry Davis as the first superintendent. The
American Ephemeris and Nautical Almanac was first published in 1852, containing data for the year 1855. Its data was originally calculated by human "computers", such as
Chauncey Wright and
Joseph Winlock. Between 1855 and 1881 it had two parts, the first for the
meridian of Greenwich contained data on the
Sun,
Moon,
lunar distances,
Venus,
Mars,
Jupiter, and
Saturn, which was published separately as
The American Nautical Almanac. The second part contained data for the
meridian of Washington on the Sun, Moon, planets, principal stars,
eclipses,
occultations, and other phenomena. Beginning in 1882, data for
Mercury,
Uranus, and
Neptune was added to the first part, with eclipses, occultations, and other phenomena forming a separate third part. In 1916,
The American Nautical Almanac ceased to be a reprint of the first part of the
American Ephemeris and Nautical Almanac, becoming a separately prepared volume for the navigator. In 1937, the
American Ephemeris and Nautical Almanac was divided into seven parts, with data for the meridian of Washington substantially reduced, then eliminated beginning in 1951. Data for
Pluto was added in 1950. Beginning in 1960, all parts except for a few introductory pages were jointly calculated and typeset by the American Nautical Almanac Office and
Her Majesty's Nautical Almanac Office but published separately within
The American Ephemeris and Nautical Almanac and
The Astronomical Ephemeris, a new name for the old British title
The Nautical Almanac and Astronomical Ephemeris. Beginning in 1981, the title
The American Ephemeris and Nautical Almanac and the British title
The Astronomical Ephemeris were completely merged under the single title
The Astronomical Almanac. == See also ==