The Vicissitudes of a Scientific Institution: A Decade of Change at the Paris Observatory

This is, of course, the beginning of the first sentence in A tale of two cities, a long unit which contains several other, perhaps equally appropriate, contrasts.

The most convenient compilation of French observatories and the works accomplished in them is still G. Bigourdan's Histoire de l'astronomie d'observation et des observatoires en France, the first part of which, de l'origine à la fondation de l'Observatoire de Paris, appeared in 1918, while its second, les anciens observatoires de Paris et de sa banlieue, depuis la fondation de l'Académie des Sciences jusqu'à la fin du XVIIIe siècle, was published in 1930. For some more recent considerations, see Hahn Roger , “Les observatoires en France au XVIII^e siècle”, in Enseignement et diffusion des sciences en France au XVIII^e siècle, ed. by Taton René (Paris, 1964), 653–8.

Both of these problems are dealt with extensively in the most fundamental study of the Observatory, Charles J. E. Wolf's Histoire de l'Observatoire de Paris de sa fondation à 1793 (Paris, 1902). See pp. 186–93, for example, for details on specific instruments and individuals involved in their removal. As for the building itself, the problem stemmed from the deteriorating effects of water seepage through the supporting vaults of the building's flat roof. See ibid., 301. See also the following reference. Another general work containing materials on much of the subject matter herein, although rarely with adequate documentation, is Fayet Joseph , La Révolution fran&çaise et la science, 1789–1795 (Paris, 1960).

He did so in the tenth of his letters, written in Paris on 16 May 1769: Bernoulli Jean , Lettres astronomiques où l'on donne une idée de l'état actuel de l'astronomie pratique dans plusieurs villes de l'Europe (Berlin, 1771), 134–41 (quoted passage on p. 140). Referring to much the same period, Jean Dominique Cassini said that it was necessary to conduct visitors — presumably such as Bernoulli — under the vaults with considerable precaution because of frequent detachment of rocks therefrom. See his Mémoires pour servir à l'histoire des sciences et à celle de l'Observatoire de Paris (Paris, 1810), 3.

Bernoulli , Lettres …, 140–1.

There is no major study of the Cassini ‘dynasty’, unless one wishes to invoke the rather hostile accounts of each that J.-B.-J. Delambre placed in his Histoire de l'astronomie moderne (2 vols Paris, 1821), ii, 686–804 (Cassini I) and in his Histoire de l'astronomie au dix-huitième siècle (Paris, 1827), 250–75 (Cassini II), 275–309 (Cassini III), and 309–13 (Cassini IV). A convenient modern survey with good bibliographical references may be found in René Taton's articles on all four Cassini in the Dictionary of scientific biography, ed. by Gillispie C. C. (New York, 1970–1980), iii, 100–9.

Taton recently added some new details to the story of the first Cassini's arrival in Paris and at the Observatory in his “L'Observatoire de Paris à l'époque de Roemer”, in Roemer et la vitesse de la lumière, with preface by René Taton (Paris, 1978), 99–112.

Wolf , Histoire …, 303–4.

Ibid., 230. The memoir in which he did so seems to be lost.

Ibid. , for, although the letter was published by Cassini in his Mémoires (p. 187), certain passages of it were there deleted. As will be seen later, that original 3000 livres salary was subsequently reduced to 2700.

The royal brevet is in Wolf , Histoire … (ref. 3), 231–2.

Actually, the years between 1776 and 1784 produced many appeals by Cassini — suggesting solutions ranging from quite ambitious and expensive to small-scale, inexpensive, and temporary — but no action by either the government or the Academy. On those proposals, see ibid., 234–41. One of the temporary and inexpensive proposals was to employ a newly-invented cement to forestall further damage to the vaults. This provoked the opposition of “l'académie d'architecture”, as seen in two letters written by J. E. Montucla, the historian of mathematics, who was, at this time, the “first clerk” of the director of buildings. Those letters, of July and August 1778, are preserved in the Bibliothèque de l'Observatoire (hereafter BdO) under the designation of B 4, 11. (B 4, 9–12 is entitled Lettres autographes de divers auteurs; subsection 11 contains those of authors whose names begin with L and M).

BdO, D 5, 37, pp. 1–5. This manuscript bears on its cover the following: Cassini IV, Memoirs Pour Servir à l'Histoire de l'Observatoire et des Sciences. It contains copies of various documents bearing upon the reorganization of the Observatory, and represents, essentially, a consecutively-paged collection of the “Pièces Justificatives” which Cassini placed at the end of his published Mémoires. (Thus, e.g., pp. 1–5 of the manuscript correspond to pp. 151–7 of the Mémoires.) Since it contains some items not published by Cassini, however, it seems wiser to cite this source. The originals of most of these documents may be found in D 5, 38/2, i.e., the second folder, entitled Papiers Relatifs à l'Éstablissement fait à l'observatoire en 1784, of a collection bearing the simple designation Observatoire de Paris.

See below, Section III and ref. 81.

That action was, of course, recorded in the register of the minutes of the meetings of the Academy for that year, all of which are preserved in the Archives de l'Académie des Sciences (hereafter AAdS) (Registre, 1784, fol. 142). See also Cassini , Mémoires (ref. 12), 11.

BdO, D 5, 37, p. 6. Although there is no mention of this letter in the Registre, it has been preserved in AAdS, dossier Cassini IV.

BdO, D 5, 37, pp. 7–11.

Wolf , Histoire … (ref. 3), 234–7. Actually, the class of astronomy as a whole decided for Cassini and his project (the original of which is in BdO, D 5, 39/1, folder entitled Réparations urgentes exigées par les batiments de l'Observatoire. Instruments qui lui manquent). Since the Academy was then in the midst of negotiations looking to an expenditure of 12,000 livres elsewhere, however, the project was deferred.

AAdS, Registre, 1784, fols. 195–7.

To which he offered to give his own books and manuscripts ( Cassini , Mémoires (ref. 12), 155).

BdO, D 5, 37, p. 14. Cassini made this remark in a note that he appended to his copy of the commission's report.

BdO, D 5, 37, p. 15.

Ibid., pp. 16–17.

The statute occupies pp. 19–25 in ibid.; p. 18 contains a letter from Breteuil (Versailles, 27 February 1785) stating that the King had accepted the project in all its parts.

Joseph Jérôme Lefran&çais de Lalande, Bibliographie astronomique; avec l'histoire de l'astronomie depuis 1781 jusqu'à 1802 (Paris, an XI [1803]), 571.

BdO, D 5, 38/1. The second item in that folder, Papiers Concernant Mrs les Elèves, is a letter from Levesque of 4 January 1785, at which time he was looking for a replacement.

Lalande , Bibliographie … (ref. 25), 491.

See, for example, ibid. , 557. Lalande also employed him for his own series of Ephémérides (ibid., 539).

BdO, D5, 38/1.

His letter of regrets (Constantinople, 26 February 1785) is preserved in BdO, B 4, 12. He was not, at the time of its writing, an “imperial professor”, but he knew that he was soon to become one.

BdO, D 5, 38/1, the sixth item in which concerns Nouet and his background, and is entitled simply “Mémoire”.

“Première publication des premières tables de la planète Herschel (par Dom Nouet)”, Connaissance des temps … pour l'année 1787 (Paris, 1784), 176–204.

BdO, B 4, 11 bis contains a letter from him written on that island.

BdO, D 5, 38–1 (item 8).

A letter from the abbé to Cassini, of 26 September 1785, relates Nouet's arrival at Brest (BdO, D 5, 38/1 (item 9)).

An item dealing with Cassini's request for the establishment of a chapel at the Observatory, arguing, among other things, the inconvenience of that building's location, may be seen in ibid. (item 7). It is dated 3 January 1785, but this must be incorrect since Nouet had not then been appointed. Moreover, the d'Angiviller response (BdO, B 4, 9) is dated Versailles, 25 January 1786.

This occurred in 1788, and it was not an easy negotiation. It involved several exchanges between the abbé and Cassini during the course of which the former indicated an intention of establishing an observatory at the abbey and recalling Nouet to head it. These exchanges, as well as two letters from the abbé to his religious superior, are preserved in BdO, D 5, 38/1 (items 10–17).

Ibid. (item 18) for the “note remise par Mr Jeaurat”.

The manuscript “Papers on the students” contains no materials on Ruelle. The only details in print are those provided in Devic J. F. S. , Histoire de la vie et des travaux scientifiques et littéraires de J. D. Cassini IV (Clermont, 1851), 212. Wolf (Histoire … (ref. 3), 264) based his account upon Devic's, but provided in addition the name of the horologer. Devic stated that his information was drawn from “des notes de M. de Cassini”. Long presumed lost, Cassini's “Mes Annales” were located recently by Roger Hahn in the Bibliothèque Municipale de Clermont-en-Beauvais, where they are designated as Mss-4 D. It is in a section therein (pp. 48–51), entitled “4 Octobre 1793 — Ma Sortie de l'Observatoire”, that he provides brief descriptions of all of the students. I should like to thank Professor Hahn for allowing me the use of his copy of this important document.

BdO, D 5, 38/1 (item 19), for the letter extending this offer.

Lalande , Bibliographie … (ref. 25), 596.

Ibid., 599.

Ibid., 604.

AAdS, Registre, 1786, fol. 114.

Ibid., fols. 123–4. The original of this report may be seen in the Bibliothèque National, Ms. Fr., n.a. 3258, fol. 133.

BdO, D 5, 37, p. 28, for a copy of that Breteuil letter. Even this restricted account of the 1748/5 reorganization makes it clear that Taton's statement that the Observatory “had fallen into a doze by the eve of the French Revolution” is not justified ( Taton René , “The French Revolution and the progress of science”, Centaurus, iii (1953), 73–89, p. 85). Fayet , La Révolution … (ref. 3), 136, echoed that view when he characterized as “exact” the following statement: “In his Tableau de Paris, Sebastien Mercier wrote, on the eve of the Revolution: The Observatory is falling into ruins and astronomical observations are being made everywhere other than at the Observatory”.

The belief in a conspiracy of the “aristos” was not only an important element in many of the events of the early Revolution, but continued to influence developments at later stages as well, although coming to be associated with “suspects” of diverse backgrounds. For the early manifestations, see, for example, the many relevant passages in Lefebvre Georges , The coming of the French Revolution (translation by Palmer R. R. (New York, 1959) of Quatre-vingt neuf (Paris, 1939)).

For the statement, see Cassini , Mémoires (ref. 4), 35–36. That his experience was not atypical is revealed by a similar fate of a telescope placed in the dome of Les Invalides by Gaspard Prony in 1792, probably in connection with the work of the Bureau de Cadastre. According to Lalande (Bibliography … (ref. 25), 719), he “was forced to withdraw it by the inhabitants of the environs who perhaps found that a telescope resembles a cannon”.

He had to be brought there because the work of reconstruction of the vaults then underway had forced the abandonment of the many apartments at the Observatory.

Cassini mentions this affair and his appeal only briefly (Mémoires (ref. 4), 36 and n. 1 thereon). The fullest account in print, rather too empassioned but relieved by a humorous climax, is by Devic, La vie … de Cassini IV (ref. 39), 121–5. Wolf (Histoire … (ref. 3), 321–3), reproduced part of that account but supplemented it by the document releasing Cassini from responsibility. Cassini's “Mes Annales” deals with the affair at greater length than his Mémoires; indeed, pp. 163–70 therein, treating “Quelques Anecdotes Particuliers Sur La Révolution”, are concerned primarily with what he there called “La Grande Visitte”.

The assembly's document has been printed in Wolf, Histoire … (ref. 3), 324–6. There was, in fact, one further visit even after this. On 31 July 1793, the Convention's Comité de Sureté Générale — the body that officially presided over the Revolutionary Tribunal of the famous, or infamous, Reign of Terror — ordered one of its members to go to the Observatory the next day in order to determine the truth of the accusation that the ex-minister Roland was hiding there. For the order and the negative report, see ibid., 326–8. The relevant documents, or copies thereof, have been preserved in BdO, D 5, 40. The suspicion may have stemmed from the fact that Lalande had earlier used observatories under his control to such ends.

Cassini , Mémoires … (ref. 4), 36.

There are no documents to support the charge that Ruelle was the worst of the lot, although Cassini suggested such in “Mes Annales”, and Devic published that charge. see Devic, La vie … de Cassini IV (ref. 39), 213. Despite the lack of evidence, however, it is a quite believable accusation, particularly in light of later developments to be treated below.

Wolf ( Histoire … (ref. 3), 329) gives only a very brief account of this episode, while Devic's treatment ( La vie …de Cassini IV (ref. 39), 187–8) is so confused that it even dates the affair in 1792. Fortunately, both Perny's letter (of 30 December 1789) and Cassini's note have been preserved (BdO, D 5, 38/1 (item 20)).

Devic , Le vie … de Cassini IV (ref. 39), 209, quoting from “Mes Annales”.

Wolf mentioned this accusation only in passing, with the suggestion that he would return to it later. Unfortunately he did not do that, so that any documentary basis that he may have had remained unstated (Histoire … (ref. 3), 266). I have not been able to find anything further on this matter.

This appears to be completely speculation by Wolf. See ibid., n. 1 on p. 343. See also below, ref. 86.

Lalande , Bibliographie … (ref. 25), 620.

Ibid., 625.

BdO, D 4, 25–27, passim.

AAdS, Registre, 1789, fol. 224 (1788); 1791–I, p. 266 (1789); 1792, pp. 60 (1790), 294 (1791).

On Borda and his important perfection of Tobias Mayer's invention, see Mascart Jean , La vie et les travaux du chevalier Jean-Charles de Borda (1733–1799) (Annales de l'Université de Lyon, nouvelle série, ii, fascicule 33; Lyons and Paris, 1919). For a broader context, Daumas Maurice , Les instruments scientifiques au XVIIe et XVIIIe siècles (Paris, 1953). For Mayer's original invention and its contemporary significance, see Forbes Eric G. , The birth of scientific navigation (Greenwich, 1974).

The record of these observations is preserved in BdO, D 5, 6, under the title of Observations au cercle entier, 1790–1792.

For good surveys of the establishment of the metric system, the first fairly technical and the second quite general, see Bigourdan Guillaume , Le système métrique des poids et mesures (Paris, 1901) and Favre Adrien , Les origines du système métrique (Paris, 1931). The original call for the establishment of a universal measure of length in 1789 had advocated (as had Picard in the 1670s) that of the seconds-pendulum. After the collapse of negotiations with England to that end, however, the decision was made in favour of a more ‘natural’ base which would not include the extraneous element of time. Still, since it was considered desirable to establish the exact relationship between those two lengths, the pendulum observations — carried out largely by Borda — were very important. Indeed, Borda seized the opportunity provided by the Academy's public meeting in November 1792 to make known the progress of the various operations involved, but especially of these. AAdS, Registre, 1792, p. 293.

Their resultant work is, of course, the fundamental source on this operation: Delambre Jean-Baptiste-Joseph and Méchain Pierre-Fran&çois-Auguste , Base du système métrique décimal, ou mesure de l'arc du méridien compris entre les parallèles de Dunkerque et Barcelone, exécutée en 1792 et années suivantes, par MM Méchain et Delambre (3 vols, Paris, 1806–10). Actually, Cassini — who had participated in the geodetical operations undertaken to establish the longitudinal difference between the observatories of Greenwich and Paris in 1787 — had originally been named one of the arc measurers, but resigned that appointment in early May of 1792. Delambre later stated that his reason for doing so was purely and simply a product of his political opinions — which did not permit him “a single connection with a government he did not wish to recognize” ( Delambre J.-B.-J. , Grandeur et figure de la terre , ed. by Bigourdan G. (Paris, 1912), 205). This was not the case, however, since he had rather compelling personal reasons — most importantly, the fact that the arc operations would have necessitated a prolonged absence from his aged mother and five young children who had become his sole responsibility since the death of his wife in April 1791. On these and other motivations, see Devic , La vie … de Cassini IV (ref. 39), 155, 156, 158, and Mascart , La vie … de Borda (ref. 62), 504. Since he participated in the pendulum observations with Borda, there would not seem, in any event, to be any substance to Delambre's suggestion.

BdO, D 5, 37, pp. 37–38. Unfortunately that memoir's address is not sufficiently precise for us to know whether the Lebrun in question was Pierre-Henri-Hélène-Marie Lebrun, a later active and ultimately guillotined revolutionist who, apparently, had earlier engaged in studies at the Observatory. See Scott Samuel F. and Rothaus Barry (eds), Historical dictionary of the French Revolution, 1789–1799 (2 vols, Westpost, Conn., 1985), ii, 575–6.

Actually, there is no evidence of these complaints by the students, and it may well be that Cassini's argument in support of them was simply in the nature of a tactic.

Printed in Wolf , Histoire … (ref. 3), 332, from Le Moniteur of that date.

That bald statement leaves a considerable discrepancy, since the total of 8700 livres is some 3000 more than his summary accounted for. Cassini's memoir was far more detailed, showing a total of 2200 livres for the student salaries, 200 livres for an annual encouragement payment to the one of their number who had made “some discoveries in the heavens or shown the most zeal during the year”, 2400 livres for the maintenance of instruments, 600 livres for the support of the library, and 600 livres for “heating and lighting in the offices and the students' quarters, registers, paper and other office expenses”.

BdO, D 5, 38/3.

For a good brief treatment of 10 August 1792 and its immediate aftermath, with further bibliographical references, see chap. 13, “The Second French Revolution, August-September, 1792”, pp. 227–47 in Lefebvre George , The French Revolution from its origins to 1793 , transl. by Evanson Moss Elizabeth (New York, 1962). Roland, the man later searched for in the Observatory, had been removed from direction of the Ministry of the Interior in January 1793, while Garat was named his permanent replacement in March. See Scott and Rothaus (eds), Historical dictionary … (ref. 66), i, 424–5.

This letter has been printed by Wolf (Histoire … (ref. 3), 337–8), who locates it in BdO, D 5, 3. That citation appeared incorrect to me, and at my request Mme Feuillebois, former librarian of the Observatory, combed that collection and other, more likely collections in search of the letter. She was unable to find it.

Wolf , Histoire … (ref. 3), 338.

Ibid., 333.

Ibid., 338–9.

Ibid., 339.

Ibid., 340.

The standard work on that change is Hamy Théodore Ernest , Les derniers jours du Jardin du Roi et la fondation du Muséum d'Histoire Naturelle (Paris, 1893). Hamy's work may be more conveniently consulted as the first 162 pages of a study entitled Centenaire de la fondation du Muséum d'Histoire Naturelle; pp. 1–70 make up the text, which is followed by the justificative pieces, which include all the relevant letters, decrees, etc.

As with all areas of Revolutionary history, works on the Girondist-Jacobin struggle and the subsequent Terror are legion, but, like the situation with 10 August 1792, one can recieve an excellent introduction in chap. 2, “The Revolutionary Government (1793–1794)”, pp. 39–136 in Lefebvre Georges , The French Revolution from 1793 to 1799, transl. by Stewart Hall John and Friguglietti James (New York, 1964).

Wolf ( Histoire … (ref. 3), 341–2) provides only brief extracts of the project which Cassini published in full in his Mémoires (ref. 4), 182–208. Also, BdO, D 5, 37, pp. 43–65.

Indeed, this part occupies pp. 182–203 in his Mémoires (ref. 4).

The salaries of the first, second, and third assistants were to be 1200, 1100, and 1000 livres, respectively.

So he said in a letter to Lakanal found in that deputy's papers in the Howard Memorial Library of New Orleans and published, in translation, in Dawson's Charles John Lakanal the regicide: A biographical and historical study of Joseph Lakanal (University, Alabama, 1948), n. 38 on p. 45. For problems arising from that letter, see below, ref. 88.

This was stated by Cassini in a note that he appended to the memoir in his manuscript collection of documents that he undertook in preparation for publishing his Mémoires, but which he did not publish, BdO, D 5, 37, pp. 65–66. All the quotations in this and the next two paragraphs are from this source, unless otherwise noted.

In the briefer account of this episode that he published in the text of his Mémoires (pp. 37–38), Cassini stated that the reason it was not presented was that he had cited “and with eulogies, Louis XIV, his successors and the names of several proscribed ministers (it must be remembered that the name of King was then the greatest blasphemy that one could utter …)”.

Although apparently only a reference to Garat's request of the previous June, Wolf here introduced the earlier-mentioned possibility — without any foundation — of a petition from the students. Unhappily, the date at which Lakanal — who served as president of the Committee from 1 August to 3 September — was assigned to that task is unknown. It was only when he brought in his report on 2 August, that the Committee's minutes tell us that he had been so “nommé”. See Guillaume James (ed.), Procès-verbaux du Comité d'Instruction Publique de la Convention Nationale (6 vols, Paris, 1891–1907), ii, 214–15 (hereafter P-v du C.i.p.). In “Annexe C” to that meeting (pp. 218–27), Guillaume printed many of the documents relative to this entire episode, including Cassini's manuscript note cited above.

A good summary of his effort in that direction, including a reproduction of some of the relevant correspondence, etc., may be found in “Lakanal et l'Académie des Sciences”, in Guillaume James , Etudes révolutionnaires (2 vols, Paris, 1908–9), i, 113–26. See also Lavoisier Laurent Antoine , Oeuvres , ed. by Dumas J. B. and Grimaux E. (6 vols, Paris, 1862–93), iv, 615–24, and Grimaux Edward , Lavoisier, 1743–1794, d'après sa correspondance, ses manuscrits, ses papiers de famille et d'autres documents inédits (Paris, 1888), esp. pp. 237–42. See also below, ref. 97.

Dawson contented himself with printing the letter (see above, ref. 83), providing only a very brief description of the “essential”. Indeed, it is not clear that the letter still had the project and the “essential” attached. This new “note” terminates Cassini's manuscript account of the fate of his original long memoir. It ought to be mentioned that I have herein reconstructed the later part of this episode — the resubmission phase — in accordance with what appears to be the most reasonable chronology of events. Wolf's treatment (Histoire … (ref. 3), 341–3) is completely inadequate, giving the impression that the original memoir, sans introduction, was actually submitted to the Committee, and stating outright that the deferment on 2 August was the result of the favourable impression made by that memoir on “several members of the committee …”. Guillaume does not commit himself at all on a resubmission. Nor does he even mention that the minutes are silent on the question of “new explanations”, although, since he was, of course, unfamiliar with Cassini's letter to Lakanal, he could not have known that Cassini actually sent them to Lakanal. Unfortunately, the real key to the problem is missing: Cassini's letter is undated. Dawson would have it written prior to Lakanal's proposal, suggesting specifically the last days of July or the first day of August. This appears erroneous, however. For one thing, Cassini himself states that his informant told him of the proposed reorganization “au mois d'août”. For another, how would that informant have known the tenor of Lakanal's proposal before having heard it on 2 August?.

Guillaume included a selection from the Convention's minutes of that date ( P-v du C.i.p. , ii, 224–5). Cassini misdated the account he placed in “Mes Annales”, pp. 33–36, which reads “30 Août 1793 — Nouvelle organisation de l'observatoire”.

Dawson , Lakanal … (ref. 83), 47.

BdO, D 5, 37, p. 68. The letter has been printed both by Wolf (Histoire … (ref. 3), 345) and by Guillaume (P-v du C.i.p., ii, 227). Curiously, Cassini's own treatment in “Mes Annales”, pp. 37–39, is, again, misdated, reading “6 Septembre 1793—Ma Demission”.

BdO, D 5, 37, item entitled “Exposé” (see below, ref. 94). Devic (La vie … de Cassini IV (ref. 39), 201), quoted the passages below, but did so both incorrectly and, as usual, without any indication of their source.

This inventory of the “instrumens d'optique et d'astronomie” was the most important of three inventories and was published by Cassini in his Mémoires (ref. 4), 208–17. The other two were devoted to the Observatory's geographical objects and to its holdings in manuscripts and books. Copies of all of these are preserved in BdO, D 5, 37/5, while what appears to be the original of the instrument inventory may be seen in D 5, 37/1. Actually, the latter was misdated and it is necessary to read “le dix-neuvième jour du premier mois de l'an II …” as 19 September. See Wolf , Histoire … (ref. 3), 349. The geographical inventory was earlier, the library inventory later.

These incidents form the subject matter of an “Exposé” that Cassini wrote and placed at the end of the materials he collected to serve as documentation for his printed Mémoires. He decided against publishing it, however, so that the “Exposé” and the “Pièces justificatives de l'Exposé précédent” — consisting of copies of his letters, original letters of Perny, Lakanal, and Grégoire, and terminating with a “Certificat des Commissaires de la section de l'observatoire” of 5 October 1793 — are on unnumbered pages (BdO, D 5, 37). Guillaume has published the whole collection as “Annexe B” to the meeting of 24 September 1793 ( P-v du C.i.p. , ii, 475–87). Wolf, respecting Cassini's decision, published only the documents ( Histoire … (ref. 3), 353–9). Devic, in addition to unidentified selections from the “Exposé”, published some of the correspondence (La vie … de Cassini IV (ref. 39), 195–206, 514–17).

Lakanal much later undertook to publish a collection of documents in his own self-glorification of services he rendered to the sciences generally and the Academy specifically ( Lakanal Joseph , Exposé sommaire des travaux de Joseph Lakanal (Paris, 1838)). Even though intended to justify his claim that his “unique ambition was always to serve my country while defending the cause of letters” (p. 197), the Exposé is, nevertheless, a handy collection of decrees, letters, etc. of great interest to this study. Unfortunately, these materials are poorly arranged and often undated.

For possible explanations of the switch in reporters from Lakanal to Grégoire, see Guillame , Etudes révolutionnaires (ref. 87), i, 119–20. As will be seen below, a similar exchange was to take place in a later reorganization of the Observatory.

There are many traditional treatments of the Academy and its suppression at this time, but all have been superseded by Roger Hahn's magisterial The anatomy of a scientific institution: The Paris Academy of Sciences, 1666–1793 (London, 1971). Although the diverse reasons for the Academy's suppression are beyond the scope of this article, it seems well to point out that one explanation of it suggests a reason that should have applied to the Observatory as well. C. C. Gillispie proposed in 1957 that the Academy met its end because it was seen as a centre of Newtonian science by Jacobins possessed of a philosophy of science that made them anti-Newtonian, a position he justified — in part — by contrasting its fate with that of the former King's Garden, the alleged focal point of a more democratic and less mathematical “Rousseauistic” science (see his “The Encyclopédie and Jacobin philosophy: A study in ideas and consequences”, in Critical problems in the history of science , ed. by Clagett Marshall (Madison, Wis., 1959), 255–89). This book also contains (pp. 317–20) the comments of Henry A. Guerlac on Gillispie's paper and on one attacking it. The comments show that Guerlac, who had first enunciated this view in a paper presented in 1954 but not published, had withdrawn somewhat from his earlier position. Gillispie, on the other hand, continued to advocate it, in a more general survey entitled “Science in the French Revolution”, published (but without documentation) in Behavioural science, iv (1959), 67–73. Although it is true that the Museum was later to be favoured by several Revolutionary enactments (see, e.g., ref. 137 below), the science of astronomy and astronomical institutions are really far more relevant to an analysis of the Guerlac-Gillispie argument. Astronomy is, after all, the Newtonian science par excellence. Should not the Jacobins, therefore, if they were to apply their philosophy of science consistently, have suppressed the Observatory, of whose existence they were well aware? But the reorganization being discussed here, although resulting in Cassini's resignation from his position in the Observatory, left that institution very much in existence.

Thanks to Condorcet's participation in the Revolution — which saw him in hiding as a Girondist in the summer of 1793 — it was necessary for the Academy to be served by a series of vice-secretaries, which included Cassini, Lalande, and Bory. Cassini was named to that post on 13 June 1792 (AAdS, Registre , 1792, p. 173). Lalande began his occupancy on 21 November 1792 ( ibid. , p. 298). Because of the lack of formal minutes for 1793, it is impossible to say precisely when Bory was elected, although there is no question but that he was serving as vice-secretary at the moment of the Academy's suppression. It was certainly partly because he held that position during a time of considerable change within the Academy that Cassini devoted one of the longest sections in “Mes Annales”, pp. 1–30, to “9 Août 1793, Destruction de Lacadémie [sic] Royale des Sciences”.

Dawson , Lakanal … (ref. 83), 47. It was also his tone toward Cassini that caused Guillaume to reject Lakanal's self-characterization as a fighter “against barbarism” (Etudes révolutionnaires (ref. 87), i, 126).

P-v du C.i.p., ii, 458.

Although he stated in his Mémoires (ref. 4, p. 38) that he withdrew on 6 October, he elsewhere said the 4th. See, for example, “Mes Annales”, in which pp. 48–51 are entitled “4 Octobre 1793 — Ma Sortie de l'Observatoire”, and his Les Fastes de l'Astronomie. Tableaux Chronologiques de l'Histoire et des Progrès de cette Science Depuis la Création du monde jusqu'au dix-neuvième Siècle Après Jésus-Christ. Suite des Mémoires pour Servir à l'Histoire des Sciences de J. D. Cassini IV. The latter three-volume chronicle and an accompanying “2e partie” made up mainly of tables is preserved in BdO, D1, 25–28. It is in D1, 27, “T. 3 — IVm Vm et VIm Age. 1600–1800”, p. 136 that he dates his departure with the reference to Cassini I. Moreover, since the “Certificat” of the section commissioners (see ref. 94) reveals that their examination of the Observatory began at 5 p.m. on the afternoon of the 4th, there would have been no reason for his staying on. Indeed, their report testifies to the condition in which he had left things, so that for him to have stayed on — in view of the kind of charges and exchanges being made, the last one of which occurred at 4 p.m. on 4 October — would have made him prone to new attacks. Further, one of the issues of the exchanges had been the date of his departure, and one of their results the granting to him of a delay which permitted him to remain until 3 October. And, since Cassini states both that he “did not abuse” this indulgence and that he had “terminated his removal” on that date, he seems actually to have departed on 3 October. But, he then took his keys with him, returning for the examination on the following day and turning over the keys only after it was completed.

The only significant biography, and that woefully inadequate on these matters, is Forni Jules , L'astronome Bouvard (Chambery, 1888).

On that development generally, see Mathiez Albert , “La mobilisation des savants en l'an II”, Revue de Paris, xxiv (1917), 542–65.

He related this to Adolphe Quetelet when the latter, later the Director of the Observatory of Brussels, was a student in Paris. Quetelet recounted it in his Sciences mathématiques et physiques au commencement du XIXe siècle (Brussles, 1867), 613. Unfortunately, he did not say, nor have I been able to determine, where he was teaching.

P.v du C.i.p., ii, 595.

Although the minutes do not state, it is only logical to assume that these were “his” volumes. Why else would he have submitted them? Moreover, the number of volumes is that which he had prepared.

P-v du C.i.p., ii, 592.

For Lakanal's work “on mission”, see Marcus M. , Lakanal (Paris, 1879). This, in fact, is almost the only value of this slight biography.

For very brief biographical data on Bouquier, see P-v du C.i.p., ii, pp. xcii–xciii.

Ibid., 649.

BdO, D 4, 27.

Quetelet, Sciences … du XIXe siècle (ref. 104), 613.

P-v du C.i.p. , ii, 85. The quotation is from a proposal read at the Committee's meeting of 20 July 1793. Grégoire was appointed to prepare a decree on the subject, which he did at its meeting of the following 3 September ( ibid. , 356). Although adopted by the Committee, it was not presented to the Convention until more than a year later (see below, Section V and ref. 154). Jeaurat, however, apparently knew of that decision of the Committee, which took cognizance of his request at the meeting of 5 November (P-v du C.i.p., ii, 747). By that time the Committee was employing the new Revolutionary calendar (on which see below, Section IV and ref. 124), so that that date is shown in the minutes as 15 brumaire an II. Except where customary usage has made Revolutionary dates commonplace, however, all dates will be converted to their Gregorian equivalents herein.

In support of his petition he submitted a printed list entitled Indication succincte des travaux scientifiques publiés à Paris pendant quarante-trois ans par le citoyen Edme-Sébastien Jeaurat, le plus ancien des ci-devant Académie des sciences, etc., to which he attached a note, the burden of which was to prove his right to a place on the Commission of Weights and Measures by virtue of his seniority. The title of his submission and the existence and content of the note are made known in the materials annexed to the meeting of 13 November ( ibid. , 822). On the establishment of the “metric commission”, see Oeuvres de Lavoisier (ref. 87), iv, 660–78.

His letter was read on 13 November ( P-v du C.i.p. , ii, 814). Guillaume printed it, along with the materials mentioned in the previous note, in Annex B to that meeting (ibid., ii, 822).

Ibid., ii, 824. Curiously, that task was assigned to Arbogast.

Ibid., iii, 214. Ferry seems to have received a Jeaurat letter of 26 November, the contents of which, while not known to me, must have been as described. This appears to have been Ferry's only real occupation with Observatory matters.

Ibid. , iii, 294, meeting of 24 January 1794. Bouquier was here named reporter. Apparently it was this same item that arose again on 7 February (ibid., iii, 360).

The minutes for 30 April state only that the Committee “passes to the order of the day” on a Jeaurat letter dated the previous day ( ibid. , iv, 294). In June he employed a “tactic”; he first called attention to his earlier productivity by requesting a copy of one of his memoirs that was missing from his library of his own efforts, and followed this by another expression of his desire to re-enter his lodging (ibid., iv, 722). This communication was again submitted to Arbogast.

Devic , La vie …de Cassini IV (ref. 39), 214. Cassini was guilty of nothing more serious than corresponding with an aunt who was imprisoned as a suspect. The temper of the Terror was such, however, that an individual in contact with a suspect was himself suspect. The letter denouncing Cassini, published by Devic, makes his aunt the wife of an émigré. In a refutation addressed to the Committee of General Security, Cassini pointed out the necessity of his communication with his aunt, who had been widowed prior to the Revolution (ibid., 239–40, 260).

See below, Section V.

A “project of bye-laws on the internal regulative administration of the Observatory” was then turned over to Bouquier for a report ( P-v du C.i.p. , ii, 622). The report was not made, however. On 15 November, one of the professors appeared before the Committee to request “the examination of his petition to obtain a system of organization” for the Observatory. Bouquier was again named reporter. Ibid. , ii, 825. Again he did not produce, however, so that this suggestion of possible trouble remains obscure in both origin and outcome. The minutes are thereafter silent on this question until the following 3 July 1794, where one encounters what appears to be a new submission in the statement: “The bye-laws for the Observatory sent to the Committee by citizens Perny and Ruelle” (ibid., iv, 741). As usual, the matter died right there.

The first such reference occurred on 16 October (BdO, D 4, 27).

This occurred on 21 brumaire (11 November). Although several items, including my own forthcoming article in the Annales historiques de la Révolution fran&çaise, could be cited as introductions to the Revolutionary calendar, it seems sufficient simply to refer to the work that is commonly used for the conversion of dates and contains the relevant decrees as a preface: Concordance des calendriers grégorien et républicain (Paris, 1983).

Lalande , Bibliographie … (ref. 25), 739.

They recorded their observation there in the Journal (BdO, D 4, 27, under date of 6 messidor (24 June)).

On the earlier observations there, see Bigourdan , Histoire de l'astronomie d'observation … (ref. 2), 2nd part, 70–73. The value arrived at by the professors was 21″ ( Lalande , Bibliographie … (ref. 25), 754).

These decrees were largely the work of the painter David, the chemist Fourcroy, and, as reporter for the Committee of Public Safety, the chief architect and director of the Terror, Barère. A feeling for the change in spring 1794 is given by Guillaume in his Introduction to the fourth volume of P-v du C.i.p., pp. lii–lvii. And, in the body of that text he annexed to the minutes of the meeting of 22 April ( ibid. , 248–63), a “List of decrees of the Committee of Public Safety relative to the fine arts, letters, and sciences handed down during the course of floréal an II”. Indeed, that list is considerably more detailed, although not as broad, as the indication of the decrees given by Barère himself, who, in fact, did not emphasize these as much as might be expected for a man attempting to justify his actions. See Barère Bertrand , Mémoires (publiés par MM. Hippolyte Carnot and David (d'Angers), 4 vols, Paris, 1842), ii, 141–6. Barère's role as the “Minister of Culture and Propaganda, April-July, 1794” was made the subject of a chapter in the long-needed biography of him by Gershoy Leo , Bertrand Barère, a reluctant terrorist (Princeton, 1962), 217–36. Perhaps the best general treatment of the new phase, however, is the chapter entitled “The culmination” in Palmer Russell Robert , Twelve who ruled (Princeton, 1941), 305–34. (The “Twelve” of the title refers to the members of the Committee of Public Safety).

The article-by-article discussion took place at the Committee meetings of 13 and 15 March, with the decision that the project would be communicated to the “Committees of Finances and of Public Safety, and then proposed to the National Convention” ( P-v du C.i.p. , iii, 563–70). Although the proposal was not made until a month later, Guillance printed the report and proposal as Annex A to the meeting of 15 March (ibid., 571–8). The adjournment was not the product of opposition to the particulars of the project, many parts of which, indeed, were already in the process of separate elaboration or even of execution. That, in fact, was the major reason for its failure, for the Terror mode of operation had been in the form of attacks on specific problems and their resolution by means of requisition and mobilization.

In addition to that of Paris, there were to be such institutions in Strasbourg, Brest, and Marseille. The articles relating to these establishments are: Sect. II, articles 8 and 9, Sect. III, articles 9 and 10, and Sect. IV, article 1. See additionally, on the instrumentation of instruction, Sect. IV, articles 1 and 3. P-v du C.i.p., iii, 577, 578, 580.

On the acquisition of that instrument, see ibid., iii, 554, 558, 570, and iv, 23–24, 34.

That salary was 2880 livres. See Despois Eugène , Le vandalisme révolutionnaire: Fondations littéraires, scientifiques et artistiques de la Convention (Paris, 1868), 100.

P-v du C.i.p., iii, 166–7, meeting of 17 December.

In a relative sense the astronomers did somewhat better this way, since Bouquier's plan would have given many others a salary of 3500 livres. This did not apply specifically to the professors of the Museum, with which institution he did not deal, but it might well have carried over to them since it did apply to such individuals as health instructors, etc.

In the final decree, those salaries were awarded “provisionally”. This is of no significance, however, since, as has been seen, the use of that term was simply a matter of form.

Grégoire had made that proposal at the meeting of 7 October. P-v du C.i.p., ii, 595.

A recent researcher has pointed out that in the Library of the Arsenal in Paris, “there are lists of more than 6,000 books supplied to the Museum between 1793 and 1801” ( Smeaton W. A. , Fourcroy, chemist and revolutionary, 1755–1809 (Cambridge, 1962)).

Since Robespierre's “dictatorship” had been exercised through the Committee of Public Safety, one of first and most necessary tasks facing the new masters of France was the stripping of that body's extraordinary powers. Since it could be useful when fulfilling its functions as a tool of the Convention, that body was preserved. In keeping with one of the major thrusts of the process of re-creation, however, it can be argued that the Committee of Public Institution took over its role, becoming for the Reaction what it had been to the Terror, namely, a central policy committee for the dominant group of the period.

These details were gleaned from a long note by Guillaume (P-v du C.i.p., iv, 941, n. 2).

Ibid., 917.

See the excerpt of that committee's meeting of that date in Devic , La vie … de Cassini IV (ref. 39), 518–19). His actual release seems to have taken place on 15 August, which, Devic says, curiously, was 18 days later (ibid., 317).

Guillaume implies the latter (P-v du C.i.p., iv, n. 3 on p. 917). But see below, ref. 144.

Ibid. , 931, meeting of 12 August. The Committee of Public Instruction sent the letter on to the Temporary Commission of Arts where it was read at the meeting of 22 August. The minutes of that meeting reveal far more of its contents — providing, for example, the following quotation. Tuetey Louis (ed.), Procès-verbaux de la Commission temporaire des arts (2 vols, Paris, 1912–17), i, 353–4.

There was, thus, a five-day period between its writing and its presentation. Hence, it is not unreasonable to assume that the earlier Perny letter may have experienced a similar delay. It is interesting to note, in passing, that information flowed much more rapidly in the other direction, for, as will be seen, Committee decisions made themselves felt at the Observatory on the very day that they were arrived at.

P-v du C.i.p., iv, 941.

Ibid. , 984. For the “purging” decree of the Committee of Public Safety and its implementation as regards Delambre, see Delambre and Méchain , Base … (ref. 65), i, 48–52.

P-v du C.i.p., v, 21.

Ibid., v, 492, meeting of 14 February.

Ibid., v, 86.

The question did arise again the following spring ( ibid. , vi, 297). And, the evacuation of a forger who had been given quarters in the Observatory as a result of Cassini's instrument ventures was ordered on 22 June (ibid., vi, 317). This was still not final, however; indeed, the matter was only settled under the aegis of the Bureau des Longitudes.

Lalande , Bibliographie … (ref. 25), 758.

Ibid., 739.

P-v du C.i.p., v, 431. This, of course, was quite similar to his offering to the Committee about a year earlier.

See above, ref. 113. This question came up before the Committee many many times from September onwards, because some three lists of recipients were ultimately decided upon, involving the expenditure of over 600,000 livres. See P-v du C.i.p. , v, 30, 103–5, 169, 205, 221, 239, 248, 257, 271, 359–60, 365, 372, 378, n. 3 on p. 379, 380–6, 391, 392, 436, 450, 457, 481–2; vi, 52–53, 76, 86–90, 266, 413, 431–3, 447–8, 454–5, 472, 497, 591–3, 610, 624–30. Perny accompanied his request for a recompense with a list of “his literary works” (ibid., v, 514).

Ibid., iv, 931.

Ibid., v, 364.

Ibid., v, 565.

See, under the appropriate dates, BdO, D 5, 28. Since the Journal des observations was recorded in Revolutionary dates, it has been thought wise to leave them that way here. It was, incidentally, the trial of Barère and other former members of the Committee of Public Safety that touched off the mentioned riots on 20 May 1795.

P-v du C.i.p., vi, 215.

BdO, D 5, 38.

BdO, D 5, 28.

For some bare biographical details on Bissy, see Lalande , Bibliographie … (ref. 25), 640.

Ibid., 755.

Lakanal , Exposé … (ref. 95), 207, for Laplace's letter of 17 December.

Ibid., 207–9, for his letter of 23 December.

The question of the preservation and utilization of observatories other than that of Paris had already arisen in connection with the establishment of a new national network of secondary schools in France. Thus, the report and project of a decree on the creation of the so-called central schools contained this article: “The Committee of Public Instruction will make a report on the monuments and establishments already devoted to public instruction in the sciences and arts, such as botanical gardens, natural history collections, plots destined to cultivation trials, observatories, societies of artists and scientists, which it would be well to preserve in the new instructional plan” (P-v du C.i.p., v, 309; my italics). In point of fact, no observatories appear to have been conserved for the purpose of training central school students in observational techniques. Indeed, the requested report on them was made only in connection with the background of the Bureau des Longitudes.

Actually, Grégoire had made a considerable point of that same development in his earlier report on academies. For useful introductions to the longitude problem and its solution, see Forbes , op. cit. (ref. 62), and my “A survey of the efforts to determine longitude at sea”, Navigation, iii (1952–53), 188–91, 242–9, 296–303.

Grégoire was charged “with the study on the Bureaux de Longitudes [the first specific use of that term] and Observatories to establish in the Republic …”, at the meeting of 23 April ( P-v du C.i.p. , vi, 125). The substitution was necessary because Lakanal had been named one of three members of the Committee sent “on mission to assure the execution of the laws relative to public instruction”, by the decree of the Convention on 10 April. See, ibid., pp. iii, 53, 57.

Lalande recognized Lakanal's role as founder most prominently in his history of astronomy for 1795 (Bibliographie … (ref. 25), 755). He also did so in correspondence with Lakanal, most pointedly in a letter of 19 December 1795 presenting a copy of the Connaissance des temps to the Committee and referring to Lakanal as the Bureau's creator and himself as his creature. He also thanked him on the tenth aniversary of Lakanal's appointment of him as Director of the Observatory, saying that he still referred to himself as the former holder of that title. Excerpts of these letters can be seen in Lakanal, Exposé … (ref. 95), 210–11. The former has been printed in its entirety in Boatner Charlotte H. , “Certain unpublished letters from French scientists of the Revolutionary period taken from the files of Joseph Lakanal”, Osiris, i (1936), 173–83; see esp. p. 182. For Grégoire's complaint, see Grégoire Baptiste Henri , Mémoires (2 vols, Paris, 1837), i, 356.

Fayet's account of the creation sides with Grégoire. See La Révolution … (ref. 3), 408–19, esp. p. 412.

The most convenient source for Grégoire's report, the decree itself, and the Bureau's subsequent internal règlement is the Recueil des décrets, lois et règlement concernant le Bureau des Longitudes (Paris, 1874), although all of this and more may be found scattered through vol. vi of P-v du C.i.p.

Grégoire's report made a considerable point of the English role in attacking the problem of longitude at sea — including, of course, their creation of the Board of Longitude — as an explanation of their naval supremacy.

One of the clearest cases of theoreticians' dislikes of “mere” observers, was the long delay in the election to membership in the Academy of one of the latter, namely, Charles-Joseph Messier. The feeling on the part of the former was exemplified by Laplace's sentiment that “if man had restricted himself to collecting the facts, the sciences would be only a sterile nomenclature and he would never have known the noble laws of nature” ( Andoyer Henri , L'oeuvre scientifique de Laplace (Paris, 1922), 36). See also Floquet G. , “L'astronome Messier”, Mémoires de l'Académie de Stanislaus, 5e serie, xix (1901–2), pp. xxiii–lxvii; Hahn Roger , “Quelques nouveaux documents sur Jean-Sylvain Bailly”, Revue d'histoire des sciences, viii (1955), 338–53; Marchand Charles-Emile-Honoré , “Jérôme Lalande et l'astronomie au XVIIIe siècle”, Annales de la Société d'Émulation et d'Agriculture de l'Ain, xl (1907), 82–145; xli (1908), 313–417, esp. p. 362 in the latter.

As to the separation between scientists and those who constructed their necessary instruments, it might be pointed out that, while in the 1730s the Académie des Sciences engineered the suppression of a promising Société des Arts, the same body did create its own special corps of artisans slightly more than fifty years later. See, for example, Hahn Roger , “The application of science to society: The societies of arts”. Studies on Voltaire and the eighteenth century, xxv (1963), 829–36; Daumas Maurice , “Le corps des ingénieurs brevetés en instruments scientifiques (1787)”, Actes du VIe Congrès International d'Histoire des Sciences, ii (Paris, 1953), 478–88. Despite the latter, artisan animosity toward the Academy was an important element in that body's suppression in August 1793.

All of those subjects, and many more, are examined in considerable detail in what is still the only work of any significance on the Bureau, to wit, Bigourdan Guillaume , “Le Bureau des Longitudes: Son histoire et ses travaux de l'origine (1795) à ce jour”, Annuaire (publié par le Bureau des Longitudes), 1928, Appendice A, 1–72; 1929, Appen. C, 1–92; 1930, Appen. A, 1–110; 1931, Appen. A, 1–151; 1932, Appen. A, 1–117; 1933, Appen. A, 1–91.