Primus inter pares: the place of the Bureau des Longitudes among the national
ephemeris offices

LeRoy E. Doggett
U.S. Naval Observatory

Following the demise of the Academie des Sciences, the Bureau des Longitudes
was created to plan and administer astronomical research in the new Republic. 
One of the initial duties of the Bureau was to prepare and publish the annual
almanac Connaissance des Temps.  First produced for the year 1679 for the
Academie des Sciences, the Connaissance des Temps is the oldest of the
national almanacs.  To satisfy changing needs of scientists, navigators and
the public, the Bureau has introduced other almanacs to supplement the
Connaissance des Temps.

Other national ephemeris offices have worked in friendly competition and
cooperation with the Bureau.  An important event was the publications in Great
Britain of The Nautical Almanac and Astronomical Ephemeris for 1767.  By the
end of the 18th century, important almanacs were being published in Germany,
Italy, Spain and Portugal.  Finally, the United States entered the scene with
The American Ephemeris and Nautical Almanac for 1855.

The French, British and American institutions were founded under different
circumstances to serve different purposes.  They have interacted and evolved
as a result of national and institutional priorities, as well as scientific
developments.  The Bureau des Longitudes enters its third century a with a
remarkable tradition of research in dynamical astronomy.  Its current research
program should sustain this tradition and ensure the Bureau's stature among
the national ephemeris offices.