Les procès-verbaux du Bureau des longitudes





The project of digitizing of the minutes of the weekly meetings of the Bureau des Longitudes (1795-1932) was carried out from 2014 to 2016 in partnership with the Bureau des Longitudes, the Observatoire de Paris and the Université de Lorraine (Archives Henri Poincaré) and thanks to the financing of the Digital Scientific Library (BSN5). This project had two goals: the preservation of this unique corpus of archives and the availability to researchers and the general public of this, so far, insufficiently used resource, which is of great scientific and historical interest.

The 2016 ANR project entitled "Le Bureau des longitudes 1795-1932. De la Révolution française à la Troisième République" (coordinated by Dr Martina Schiavon, UL), which followed the digitizing project, started in 2017. The objective of the project was to undertake an exhaustive study of the Bureau, especially of its history (see the blog https://histbdl.hypotheses.org/16); which would be based on the digitized minutes and more generally on any available source related to the history of the Bureau. While carrying out this project, we have considered that the use of the information contained in the minutes would be considerably improved by the knowledge of accurate historical elements regarding this Bureau, which should be made available to users.

The most exhaustive history of the Bureau des Longitudes is the one published by Guillaume Bigourdan (1851-1932), astronomer at the Paris Observatory, an outstanding member of the Bureau des Longitudes and of the French Académie des sciences. It was published in six volumes of the Annuaire du Bureau des Longitudes between 1928 and 1933, as a series of notices which represent as a whole a volume of 633 pages. Bigourdan passed away in 1932 before the publication of the last notice but considering the initial title, there is reason to believe that the story which covers the years until 1874 was intended to be continued.

The following pages include the entire text of G. Bigourdan, i.e. the texts of the six successive notices without any change or addition, in a form that is easy to use either in digital or printed format.


To achieve the completion of this document, we have been able to access the whole text of Guillaume Bigourdan’s notices which had been typed in on diskettes in 1994 by Yvon de Kergrohen, who was then administrative secretary of the Bureau, in the framework of a work led by Jean Chapront (1939-2019), who was Corresponding Member of the Bureau des Longitudes and former Director of the Service des calculs et de Mécanique céleste of the Bureau. The diskettes were fortunately found in 2014 during a move at the Bureau des Longitudes premises and were used to retrieve the text which was converted into a format compatible with existing software. The text was then thouroughly revised and corrected by several members of the ANR Steering Committee. Finally, Julien Muller adapted the text for on-line publication and inserted the figures/graphs/pictures.


Nicole Capitaine
Bureau des longitudes
15 March 2020

Please click on this link to get the full text in PDF format:

Histoire du Bureau des longitudes

The following text, also available for download in PDF format, is the transcription by Colette Le Lay of a text presented by Guillaume Bigourdan at the 1929 Congrès des sociétés savantes, entitled: La réorganisation du Bureau des longitudes, en 1854 et 1862.

La réorganisation du Bureau des longitudes