History of the Library

It was Cassini IV, who created the Bibliothèque de l’Observatoire de Paris in 1785, the last of the dynasty of astronomers who founded and directed the Paris Observatory.

In his project proposal to renovate the Observatory, presented on May 13th 1784 to the Baron de Breteuil, Minister of the Royal House (ministre de la maison du roi), Cassini IV annonces his plan in creating a library. This project, which had the support of the Baron de Breteuil, and the Count of Angiviller, Minister for the Royal Buildings (ministre des bâtiments du roi), was accepted by Louis XVI, in spite of the unfavourable report submitted by the commission of the Académie des sciences, after a special meeting on the 4th of August 1784.

The settlement document of February 26th 1785, concerning the reorganization of the Royal Observatory, has a chapter devoted to the Library. It specifies and also clarifies the various arrangements for its running and administration (articles 29 to 33) :

• Creation of the collections (books on astronomy or on geometry applied to astronomy)
• Inventory and catalog
• Right to borrow, registration, duration of the loan
• Opening times in summer and winter
• Annual report to the minister, justifying the running expenses

Observatoire Royal’s regulations, 1785

The annual allowance of 600 F, complained Cassini IV, was more than enough for the day-to-day running, but totally inadequate for the creation of collections. Faced by this difficult situation, Cassini IV donated a part of his own library. He also gained Baron de Breteuil’s authorization to earn commercially from the new printing of the Carte de la Lune, previously made by his great grand father. It was examined as a solution in order to enhance the collections. The archives were considered to be an integral part of the Library, and included registers from observations made at the Observatory between 1671 to 1791.

The French revolution did not stop the expansion of the Library. The records of April 1st 1791 list 285 volumes, including the complete set of 76 volumes of the Philosophical transactions, the works of Hevelius, the mémoires from Berlin’s academies, Vienne, St. Petersburg, Uppsala and the Journal des Savants. Two years later, the Commission des arts du Comité d’instruction publique handed an inventory to citizen Perny, a temporary director of the Observatoire de la République. The inventory listed 574 volumes.

There is still uncertainty about the Library’s exact original location. Soon after its creation, a part of the collections were apparently placed in the rooms next to the large meridian room, on the north west side. In 1692, these rooms were split to make two floors in order to house on the lower floor the machines of the Académie des sciences, and to transform the upper floor into an apartment. After the transfer of the machines to the Jardin du Roy, Cassini IV’s Carte de France was housed in 1757, until 1787. It was later transferred to Cassini’s house, located on rue Maillet.

In 1795, the Observatory’s Library was considerably growing with astronomical collections from Joseph-Nicolas Delisle (1688-1768).

As a preparation for a Traité complet d’Astronomie, which was neither finished nor published, Delisle collected throughout his life most of the published books on astronomy, as well a vast number of manuscripts, both originals and copies.

Soon after his election to the Académie des Sciences as an astronomy student (1714), he made copies of observations that were kept at the Académie’s archives. In 1719, he acquired the papers of La Hire through the son’s inheritance. The regular correspondence he kept with the most important astronomers of his time for over 60 years (1709-1767) also enabled him to obtain observations from elsewhere.

Invited to Russia in 1726 after Peter the Great’s trip to France, he established contacts with many leading German astronomers such as : Doppelmayer, the Rost brothers, Müller in Nuremberg and Altorf, Weidler in Wittenberg and Christfried Kirch in Berlin. While passing through Danzig, he acquired items that will be central for his collection : Hevelius’ written correspondence and observation notebooks.

During his stay in Russia, which lasted 21 years, he continued to build his personal collection with collated copies of observations, when unable to buy the originals : he was able to copy and translate into Latin Gottfried Kirch’s observations, before obtaining the original notebooks after the death of his son, Christfried.

The correspondence he actively kept with missionaries in China, particularly with Father Gaubil, enabled him to obtain manuscripts relating to Chinese astronomy and chronology. These thematic items in his collection increased significantly after acquiring some of Nicolas Fréret’s papers, and the correspondence of Father Souciet.

One failure marred the complete satisfaction of this happy collector. According to Guillaume Bigourdan, he could not obtain Kepler’s manuscripts, which were in Vienna.

When he returned to France, Delisle exchanged, in return for a life annuity and the title of Marine astronomer, his entire collection, which became part of the Dépt. de la Marine around 1750.

In 1795, the Comité de Salut public decided that the astronomical part of his collection should be given to the Bureau des longitudes which had just been founded. The act establishing the Bureau stipulated, in effect (chapter XVI) that "from the various centres belonging to the Nation, appropriate books, and redundant copies thereof which are in the Bibliothèque nationale, should be taken to complete the astronomical library begun at the Observatoire." The structure from the Bibliothèque Saint-Sulpice was transferred to the Observatory in order to accommodate all books. On the 21st of December 1795, the minutes of a visit held at the Observatory, signed by 5 members of the Bureau des longitudes (Borda, Laplace, Caroché, Lalande et Delambre), states that the books from the dépôt de la Marine have been delivered to Citizen Cassini’s appartment, until the library’s woodwork are in place.

The Bureau des longitudes were careful on the Library’s gradual installation. It will last for a long period and it is expensive as well : a letter from Méchain, on May 3rd 1800 highlights carpentry work in the Meridian room. Under the Bureau’s aegis and thanks to its members, donations flowed in : the collections grew with the acquisition of manuscripts from Le Monnier ; Cassini IV or his executive brought numerous manuscripts concerning his project for a Celestial History (1822-1823-1846). In 1840, Jérôme Lalande’s and La Caille’s collections were offered to the Observatoire by François Arago.

A position of secretary-librarian became essential. From 1801 onwards, the position was regularly filled : Marc Agoustenc was the first to take the position, followed by Auguste Mâchain in 1802, François Arago in 1805 and Claude Mathieu in 1807. However, the position disappeared when the new organization was established, as it was issued by the decree in 1854.

Once again, the restoration of some kind of order involved the establishment of an inventory. The Observatory keeps the written document from 1850-1851 by Ludovic Lalanne, librarian of the Institut.

The separation of the Bureau des longitudes and the Observatoire de Paris is sealed in 1854, when Urbain Le Verrier, a brilliant, but also an ambitious scientist, broke with the collegial tradition inherited from the Revolution, and arranged to be appointed as the Director of the Paris Observatory.

The January 30th, 1854 decree concerning the organization of the Observatoire impérial formalized the separation of the Bureau des longitudes from the Observatoire, and also defined the Library as a major symbol. Article 7 allowed the use of the joint library by the Bureau only during session, but the rules as announced were never adopted.

The 8th of March, 1854 minutes indicates that the library room located on the 2nd floor to the north-west of the meridian room would henceforth be reserved for the meetings of the bureau.

April 3rd, 1868 decree concerning the constitution of an Imperial Observatory Council (Conseil de l’Observatoire impérial), defined the staff’s assignments, and entrusted the archives and the library under the secretary-accountant’s care. The scientific journals and new books were to be placed in a special room used as a reading room.

But this reorganization did not last long. The astronomers found Le Verrier’s rule intolerable. In 1870, they sent to the Ministry of Public Education a Mémoire sur l’état actuel de l’Observatoire impérial (Notes on the Current State of the Imperial Observatory). They highlighted, among other serious dissensions and dysfunctions, "that the Observatory library, as well other services are in a state of total confusion. Valuable collections are absent or incomplete. The books addressed to the establishment are all received by the Director, but the books are transfered to the library at his own convenience, which is often a long time after their arrival. A sum of 600F is allocated each year to the library ; this year, this sum was not given to the library and used otherwise...." ("que la bibliothèque de l’Observatoire est, ainsi que tous les autres services, dans le désarroi le plus complet. Des collections précieuses sont absentes ou incomplètes. Les livres adressés à l’établissement sont tous reçus par le Directeur qui les donne à son heure au bibliothécaire et c’est souvent bien longtemps après leur arrivée. Une somme de 600 F est allouée chaque année pour la bibliothèque ; cette somme a été refusée cette année au bibliothécaire et employée à un autre usage")
Through a resolution on February 4th, the minister established a special commission to investigate the situation at the Observatoire : it certified that the reorganization in 1868 had failed. Le Verrier was relieved of his functions.

On March 3rd 1870, Charles Eugène Delaunay replaced Le Verrier. The decree in 1872 plans of having the Observatory inspected regularly by a commission composed mainly of members from the Bureau des longitudes, two members from the Institut designated by the Académie des sciences and five individuals chosen by the Minister from the major State’s organs. The first commission, in May 1872, indicates that during the long months of the siege of Paris, Charles Delaunay had put some order into the library’s establishment and its important manuscript collection. The Library moved in the gallery on the first floor and in the adjacent rooms, one of which had been set up as a reading room. It was opened every working day from 10am to 4pm.

After the violent death of Delaunay in 1872, and the return of Le Verrier as the head of the Observatory, the Bureau des longitudes moved to the rue Mazarine in 1874. The library collection was divided between the two institutions, but it remained intact : the Bureau only took the works which were copies, and its own archives as well, but not those on the Observatory.

The arrival of Admiral Mouchez at the head of the Observatory marked a turning point for the Library and its heritage. His ambition was to establish an important museum and a modern library...

Immediately after his appointment in 1878, the rear-admiral Mouchez created a valuable tool to survey the activity of the Observatory : the annual reports. Thankfully, it is possible to track not only the research carried out in the establishment, but also the organization and growth of the Library’s collections, as well witnessing the birth of the Museum through those reports.

Mouchez was aware that the situation at the Library was critical indeed. There were important gaps in its modern collections, which he remedied by a grant of 2.000 francs for the acquisition of works and their bindings. The state of the catalogs are no better. The prints were listed in an alphabetical order by authors, in three accessions ledgers created around 1850 ; subsequently, books were added as they arrived. Some important transfers in 1879, such as the supernumery works, which went to the Bureau des longitudes and the transfer to the Bureau central de météorologie, which was executed in 1879 of all the meteorological volumes and brochures. A modern catalog made of index cards, began in 1871, but was later abandoned due to the size of the task. The situation of the manuscripts weren’t better : the manuscript and archive collections had suffered enormously at the turn of the century : Guglielmo Libri, an important thief who was Inspector of French libraries, was a frequent visitor to the Observatory and it served him well. The catalog established in 1854 was very concise and incomplete, as shown by a written summary from a stocktaking procedure made in 1870. Then again, changes needed to take place. The accountant was clearly unable to handle the situation alone, and it was necessary to appoint specialized supporting staff. The Library’s reading room ended up being occupied for a period by the Observatory staff who were specialized in calculations.

With a profound sense of history, Mouchez pictured a major astronomical museum at the Observatory. A search for all instruments preserved at the Observatory is initiated. Somehow, the results are unsatisfying, since many instruments have been lost or destroyed. Nevertheless, they made a lucky discovery - a number of beautiful 16th century instruments were found in an archive cupboard. A grant of 5000 Francs enabled them to be presented in 1879 on the first floor, in the octagonal room of the west tower, in the central showcase. The room decorated with portraits of previous Directors of the Observatory, includes a medal collection, copies of Mercator’s spheres and five other showcases containing the metric system standards, Fresnel’s, Arago’s, Fizeau’s and Cornu’s instruments, as well various portable devices. In 1881, a second room was converted : the East Rotunda, where drawings and photographs from worldwide observatories were exhibited.

During the following years, the re-establishment of the library and the expansion of the museum were spectacular. Although they were not explicitly part of the same service, they clearly maintained close relations, since Mouchez assigns to the Museum the numerous manuscripts which arrived thanks to an active acquisition policy. In 1881, a subsidy from the Ministère de l’Instruction publique allows 453 volumes (including 28 incunabula) to be acquired from a sale : Michel Chasles’ library. Donations flowed in : the manuscripts of the 3rd edition of the Laplace’s Système du monde, Lalande’s calculations for the 1769 solar transit of Venus, observations taken by the astronomer Flaugergues (from 1782 to 1830), Arago’s handwritten notebooks, the astronomer Yvon Villarceau’s library and archives, the correspondence between the baron de Zach and J.J. Lalande (1792-1804).
A part of the letters taken by Libri from the Hevelius’ correspondence was returned to the Observatory, thanks to the Bibliothèque nationale. While, 16 portfolios of manuscripts from Delisle’s collection that were onced loaned in Russia, were returned by M. Struve, director of the Pulkovo Observatory.

In spite of the budgetary restrictions which began in 1886, the library’s collections grew considerably between 1879 and 1918, rising from 8 000 to about 22 500 volumes of works and scientific journals. In the post-war years, the growth of the collections came mainly from exchanges or donations (scientific journals, brochures), since English or American works were expensive. A few donations to the rare collections have been made, even if the rate of donations have been decreasing.

In order to maintain the collections at a high level, an exchange service with the Bibliothèque nationale was inaugurated in 1924 , which was directed under Benjamin Baillaud.

Work on the catalogs was slow, due to the shortage of staff. The accountant-librarian , Auguste Fraissinet, who managed the library until 1909, did however received help in 1883, from an employee at the Bibliothèque de l’Institut, for the creation of a catalog on books ; which will be finished the following year. As far as the manuscripts catalog, it wil be completed by Guillaume Bigourdan, two years after the death of Admiral Mouchez. The manuscripts catalog was published in 1895, in the 21st volume of the Annales de l’Observatoire de Paris with the title "Inventaire général et sommaire des manuscrits de la Bibliothèque de l’Observatoire de Paris/ (General and summary inventory of the manuscripts in the library of the Paris Observatory).

Shortly after the First World War, the practices for the description of archival records changes. In 1908, the Library followed the new instructions for the classification and cataloguing, by using the system prescribed from the governing administration of university libraries. In 1913, Léon Bultingaire published the Catalogue des incunables de la bibliothèque de l’Observatoire de Paris / (Catalogue of the Incunabula in the Library of the Paris Observatory), and began a catalog for the scientific journals using the sections of the International Catalogue of Scientific Literature. In spite of a temporary halt due to the war, and with the help of Félix Boquet, the catalog containing some 800 titles was finished in 1919. Léon Bultingaire began also a systematic analysis of the principal scientific journals and collective works devoted to astronomy, and published it in the Revue générale des travaux astronomiques from 1919 to 1924. Alfred Lacroix, perpetual secretary of the Academy of Science, gave him the task of coordinating the publication of the /Inventaire des périodiques scientifiques des bibliothèques de Paris/ (Inventory of the Scientific Journals in the Libraries of Paris), which appeared in 1924-1925 and included therefore the catalog of periodicals at the Bibliothèque de l’Observatoire de Paris.

For the manuscripts, the Inventaire général et sommaire continued with the appearance of a new numerical sequence in 1921, which starts at number 1001. That same year, a catalog of 86 medals commemorating astronomical or scientific events was created. Finally, between 1922 and 1925, an analysis on Delisle’s collection began with the creation of an alphabetic index.

Under the leadership of Henri Deslandres, who directed both observatories Paris-Meudon, henceforth united, the idea of creating a library in Meudon was born. The project was realised under Ernest Esclangon who attributed in 1928 a secretary-librarian position : M. Lamiable was the first one under this title. However, the improvement at the Library was of short duration, when in 1932 he became secretary-accountant in Paris. As a consequence, the position at Meudon was abolished.

An astronomer named Marguerite Roumens, took the project to review the catalog and also focused on the space reorganization. A large room on the ground floor was attributed to the library in the "Communs" building. The installation was finished in the spring of 1933. Cabinets that were offered by the curator at the Bibliothèque Sainte Geneviève enabled the works to be grouped together in various neighbouring rooms. Marguerite Roumens was assigned to look after the library, and kept as well her work position as the assistant of Professor Pérot.
With the help of M. Bertaud and of Mlle Markoff, she created the new catalog using an author and title index system of cards for the 12 000 volumes in the library ; about 8 000 cards.

In 1934, a subsidy from the Beaux-arts made it possible to combine two small rooms on the first floor, adjacent to the main room. Two reading rooms became available : one room was assigned for the consultation of scientific journals, while the second one was for general works on astronomy and related sciences.

Under the name of Ms. Azambuja, Marguerite Roumens was exploiting the exchange possibilities with several scientific academies, such as Stockholm, Rome, Tokyo, Leningrad and various foreign observatories. She managed to complete the periodical collections, which she later got them bound into volumes. There were 80 periodicals, and 240 publications of various observatories, institutes and learned societies.

It is only in 1954, under the direction of André Danjon, when the Library will be undertook by a librarian graduate. Afterwards, the reading rooms and storage rooms on both sites were organized and their content completed.

In Paris, the library is located in the Perrault building in the north-west wing, on the meridian floor (2nd floor), then on the 1st floor of the main gallery. In 1956-1957, the rooms on the 2nd floor were equiped with metallic storages on 3 levels with a lift. The reading room or the consultation room for archives is located on the 1st floor. Ten years later (1965-1966) the same room was refurnished and included with a mezzanine. The last conversion dates back from 1997, when the reading room was placed in the west tower.

In Meudon, the Library left the "communs" in 1971, for the building led by the Laboratoire d’Astrophysique de Meudon (LAM). Gradually, the staff team expanded and increased professionally on both sites, but nevertheless the Library kept its unity. In 1980 the Library became CADIST in astronomy-astrophysics. In 2006, it gained its status of Joint Documentation Service, and in 2009 implemented a documentation charter. Finally in 2012, a partnership was established with the Bibliothèque nationale de France of which it is now an "associated pole" ("pôle associé"). In 2017, the Library became a member of the research infrastructure CollEx.