The Measure of All Things

by Ken Alder

  Deeper grievances festered: For Méchain’s sense of being wronged, see KBD NKS1304, Méchain to Bugge, 10 brumaire VIII [1 November 1799]. Delambre discovered Méchain’s knowledge of these events when he in turn became Méchain’s scientific executor in 1805; see Delambre’s marginal note (c. 1810) on AOP E2-19, Delambre to Borda, 4 frimaire VI [24 November 1797].

  Napoleon’s first act: For Delambre’s initial election as (temporary) Secretary of the Academy on the same day that Napoleon was elected its President, see ASPV 2 (1 germinal VIII [22 March 1800], 11, 25 pluviôse XI [14 February 1803]): 126, 625, 629. The presidency of the Academy had always been (and remained) a rotating and largely honorific office, although Napoleon used it to reorganize the Academy into two branches—one for the mathematical sciences (math, physics, astronomy, geography, and the mechanical arts) and one for the physical sciences (chemistry, the life sciences, and medicine). Delambre was made Permanent Secretary for the mathematical sciences, with Cuvier made Permanent Secretary for the physical sciences. Napoleon’s new regulations provided that the Permanent Secretary be named by the branch itself, but with “the approbation” of the First Consul, meaning in effect that the position was in Napoleon’s gift. Delambre privately noted that this interference in the self-governing nature of the Academy was a novelty of which he himself did not entirely approve. Delambre, “Lui-même.”

  These circumstances go: For the proposal to revive the Balearic extension, see BL, “Procès-verbaux,” 19 fructidor X [6 September 1801]. For Méchain’s report, see AN F17 3712, [Méchain], “Rapport aux Consuls sur la continuation de la mesure de la méridienne de France depuis Barcelone jusqu’aux îles Baléares,” [September–October 1802]. Antonio E. Ten, “Le problème du 45e parallèle et les origines du système métrique décimal,” in Scientifiques et sociétés pendant la Révolution et l’Empire, 114e Congrès National des Sociétés Savantes, 1989 (Paris: CTHS, 1990), 441–52.

  “long travails”: Méchain to Rolland, 10 floréal VIII [11 May 1799], in Dougados, “Lettres de Méchain,” 114. Méchain was “alarmingly” ill in March–April 1801; see ASPV 2 (6 germinal, 1 prairial VIII [27 March, 21 May 1800]): 128, 169. The young savant whom Delambre had in mind was Lalande’s pupil Henri, then triangulating his way through Bavaria; see Lalande, Bibliographie astronomique, 701, 704, 791, 868; also Delambre, Grandeur, 223–24.

  Mercifully, the young German: For Humboldt’s pleasure at obtaining results approximating those of Méchain, see CUS, Humboldt to Delambre, 23 floréal VII [12 May 1799]. Humboldt also compared his data to Méchain’s in Humboldt to Zach, 12 May 1799, in Humboldt, Die Jugendbriefe Alexander von Humboldts, 1787–1799, Ilse Jahn and Fritz G. Lange, eds. (Berlin: Akademie-Verlag, 1973), 671–72. Humboldt’s latitude result, taken on 8 January 1799, was 41°23'28" and 41°22'59", as compared with Méchain’s result of 41°22'47", supplied in a private letter from Méchain, which Humboldt mentioned. This suggests that Méchain also knew that Humboldt planned to take a measurement at the Fontana de Oro. See Delambre’s commentary on these values in SBB Autgr. J1792(3), Delambre to Humboldt, 10 November 1807. The results were published in 1810 in a two-volume work dedicated to Delambre; see Alexandre de Humboldt and Jabbo Oltmanns, Recueil d’observations astronomiques, d’opérations trigonométriques et de mesures barométriques (Paris: Schoell, 1810), 2:3–6.

  “close to his heart”: Méchain to Rolland, 6 frimaire VII [26 November 1798], in Dougados, “Lettres de Méchain,” 91.

  “intimate union”: AN F17 3712, [Méchain], “Rapport aux Consuls sur la continuation de la mesure de la méridienne de France depuis Barcelone jusqu’aux îles Baléares,” [September–October 1802]. For state approval of the mission, see BL, “Procès-verbaux,” 5 vendémiaire XI [27 September 1802]. For Laplace’s and Napoleon’s interest in the project, see Zach’s views, undoubtedly based on information from Lalande; KBD NKS1304, Zach to Bugge, 19 January 1803.

  For diplomatic cover: For Méchain’s recruitment of Le Chevalier, see BML 26CA6, Méchain to Le Chevalier, 25 ventôse XI [16 March 1803]. For Le Chevalier’s mission, see AN F17 3712, Le Chevalier to Min. Int. [Chaptal], 8 ventôse XI [27 February 1803]. For Méchain’s acquaintance with Le Chevalier, see KBD NKS1304, Méchain to Bugge, 1 vendémiaire X [23 September 1801]. For Le Chevalier’s career in astronomy and his relations with Méchain, see Bigourdan, Astronomie d’observation, 137–40. For Le Chevalier’s murky dealings in Madrid in 1796–97, see Camille Pitollet, “Comment fut accueilli en Espagne la première ambassade française en faveur du système métrique,” Archivo de investigaciones históricas 1 (1911): 457–73. For Augustin Méchain, see KBD NKS1304, Méchain to Bugge, 1 vendémiaire X [23 September 1801]. Méchain’s eldest son, Jérome-Isaac, back safely from Egypt, had renounced astronomy—despite having discovered his own comet—in favor of a career in the Levant as a diplomatic attaché in the Dardanelles; see Méchain to Rolland, 5 jour comp. VI, 12 brumaire, 26 pluviôse, 30 prairial VIII, 18 germinal X [21 September 1798, 3 November 1799, 15 February, 19 June 1800, 8 April 1802], in Dougados, “Lettres de Méchain,” 86, 110–11, 115, 125.

  “never before”: Méchain to Dezauche, 6 germinal XII [27 March 1804], in [A.-M. Dezauche], “La dernière mission de l’astronome Méchain, 1804,” Revue rétrospective 15 (1891): 145–68, quotation on 155–57. On the British reflectors, see AN F17 3702, Méchain to Min. Int., 8 pluviôse XI [28 January 1803].

  As before, Méchain’s: For Delambre’s account of Méchain handing over his data at the last minute before his departure, see SBB J1792(3), Delambre to Humboldt, 10 September 1807.

  Méchain expected to complete: For the ten-month claim, see KBD NKS1304, Méchain to Bugge, 2 ventôse XI [21 February 1803]. For his expected departure date of February 1, see KBD NKS1304, Zach to Bugge, 19 January 1803. For his actual departure date, see BL, “Procès-verbaux,” 6 floréal XI [26 April 1803]. Méchain had originally intended to measure the length of a pendulum at Bordeaux; but he gave up this project to save time on his way south. He sailed to Barcelona from Montpellier.

  On his first day: For the delays in Barcelona, see AN F17 3712, Le Chevalier to Min. Int. [Chaptal], 25 floréal XI [5 May 1803]. Enrile had been in Paris during the preparations for the expedition; see AN F12 3712, Méchain, “Etat de position,” 12 frimaire XI [3 December 1802].

  “fantastical lie”: Coronado to Godoy, 29 December 1796, 6 January 1797, in Pitollet, “Comment fut accueilli en Espagne,” 565–70.

  “ignorant, malevolent”: AOP B4-9, Chaix to Méchain, 14 August 1804. Chaix had also assisted Méchain briefly during his first expedition in 1792. Gonzales also warned Méchain about Coronado; see AOP B4-10, Gonzales to Méchain, 24 September 1803. Le Chevalier, who had tangled with Coronado in 1796–97, also blamed him for the delays in Méchain’s mission; see AOP MS1054, Le Chevalier to Min. Int., 20 January 1806.

  Méchain’s Paris colleagues: CUS, Lalande (on behalf of the Bureau of Longitudes) to Min. Aff. Etr. [Talleyrand], 5 messidor XI [24 June 1803]. Gonzales did not think Méchain had much to worry about from the British; see AOP B4-10, Gonzales to Méchain, 30 July 1803.

  During July and August: For Méchain’s foray down the coast, see Méchain to Delambre, 30 vendémiaire XII [23 October 1803], in Guillaume Bigourdan, “La prolongation de la méridienne de Paris, de Barcelone aux Baléares, d’après les correspondances inédites de Méchain, de Biot et d’Arago,” Bulletin astronomique 17 (1900): 348–68, 390–400, 467–80; see especially 352–56. The geodetic results from this portion of Méchain’s survey were published in Jean-Baptiste Biot and Dominique-François-Jean Arago, Recueil d’observations géodesiques, astronomiques et physiques (Paris: Courcier, 1821), 1–40.

  The Spaniards, Méchain feared: For Méchain’s accusation of lying, see Méchain to Delambre, 15 pluviôse XII [5 February 1804], in Bigourdan, “Prolongation,” 364. In fact, Ibiza is visible from Montsia under the right weather conditions.

  “where he could be”: Méchain to Delambre, 15 frimaire XII [7 December 1803],
in Bigourdan, “Prolongation,” 357.

  Three days after: For the breakup of his team, see Méchain to Delambre, 15 frimaire XII [7 December 1803], in Bigourdan, “Prolongation,” 359. The Spaniards, such as Enrile’s second in command, Cini, refused to guard the reflectors, and the French (Le Chevalier) were irritated at being denied a chance to observe; Méchain to Dezauche, 4 vendémiaire, 28 pluviôse XII [27 September 1803, 18 February 1804], in [A.-M. Dezauche], “La dernière mission,” 145–47, 151–52.

  When he opened: On the poorly packed reflectors, see Méchain to Dezauche, 4 vendémiaire XII [27 September 1803], in [Dezauche], “La dernière mission,” 145–47.

  “This is truthfully”: Méchain to Delambre, 30 vendémiaire XII [23 October 1803], in Bigourdan, “Prolongation,” 356.

  To replace his renegade: On Canellas, see Méchain to Dezauche, 28 pluviôse XII [18 February 1804], in [Dezauche], “La dernière mission,” 151–55.

  A simple one-day crossing: On the trip across to Ibiza, see Méchain to Delambre, 4 pluviôse XII [25 January 1804], in Bigourdan, “Prolongation,” 361; Méchain to Dezauche, 4 pluviôse XII [25 January 1804], in [Dezauche], “La dernière mission,” 147–49.

  “It was nothing”: Méchain to Dezauche, 4 pluviôse XII [25 January 1804], in [Dezauche], “La dernière mission,” 147–49. For Ibiza, see André Grasset de St.-Sauveur, Voyage dans les Iles Baléares et Pithiuses, fait dans les années 1801, 1802, 1803, 1804 et 1805 (Paris: Collin, 1807), 249–87; Christian Augustus Fischer, A Picture of Valencia, Frederic Shoberl, trans. (London: Colburn, [1803], 1808), 290–97.

  “I thumb my nose at them”: Méchain to Dezauche, 15 pluviôse XII [5 February 1804], in [Dezauche], “La dernière mission,” 149–50.

  “my last leave-taking”: Méchain to Dezauche, 15 pluviôse XII [5 February 1804], in [Dezauche], “La dernière mission,” 149–50.

  “Hell and all the plagues”: Méchain to Delambre, 4 pluviôse XII [25 January 1804], in Bigourdan, “Prolongation,” 363.

  The town of Palma: On the sun clock, see Grasset de St.-Sauveur, Baléares, 97–99; Alexandre de Laborde, Itinéraire descriptif de l’Espagne, 2nd ed. (Paris: Nicolle, 1809), 4:441; Fischer, Valencia, 272; Sand, Winter, 69–70.

  While he waited: For the eclipse, see Méchain, “Mémoire sur l’éclipse de soleil du 20 pluviôse XII,” 10 February 1804, CT pour l’an XV (pub. frimaire XII [November–December 1804]), 476–82. For a recapitulation of Gonzales’ expedition to Mallorca in December 1792, see AOP B4-10, Gonzales to Méchain, 24 September 1803.

  “I wait with much”: Delambre to Méchain, sent 5 ventôse XII [25 February 1804], received in Palma on 22 ventôse XII [13 March 1804], in Bigourdan, “Prolongation,” 390–91.

  “Even I, who can”: Méchain to Dezauche, 6 germinal XII [27 March 1804], in [Dezauche], “La dernière mission,” 155–57. For Méchain’s deference to the Bureau, see Méchain to Delambre, 16 germinal XII [6 April 1804], in Bigourdan, “Prolongation,” 391–93; letter read to the Bureau of Longitudes, BL “Procès-verbaux,” 7 floréal XII [7 March 1804].

  The sun was stirring: On the dangers of delay and Coronado’s machinations, see AOP B4-10, Gonzales to Méchain, 24 September 1803. On Valencia, see Fischer, Valencia, 46–48, 200–204; Swindburne, Travels, 1:153–54; Alexandre de Laborde, Voyage pittoresque et historique de l’Espagne (Paris: n.p., 1806), vol. 1; Laborde, Itinéraire, 1:175–250; Richard Twiss, Travels Through Portugal and Spain in 1772 and 1773 (London: Robinson, 1775), 201.

  In all, Méchain located: For Méchain’s reconnoitering trip, see Méchain to Delambre, 11 fructidor XII [29 August 1804], in Bigourdan, “Prolongation,” 396–400, 467–70. For a description of travel at this time of year in these regions in this period, see Twiss, Travels, 213–14.

  Méchain wrote to his wife: For Méchain’s sunburn, see Méchain to [Madame Méchain?], 4 messidor XII [23 June 1804], in Bigourdan, “Prolongation,” 393–94. For the flares, see Méchain to Delambre, 11 fructidor XII [29 August 1804], in Bigourdan, “Prolongation,” 396–400, 467–70. For a description of the archbishop three years later, see François Arago, “Histoire de ma jeunesse,” in Oeuvres complètes, 2nd ed. (Paris: Legrand, Pomey et Crouzet, 1865), 1:32, 37.

  In early July: For the operations of that summer, see Méchain to Delambre, 11 fructidor XII [29 August 1804], in Bigourdan, “Prolongation,” 396–400, 467–70. On Canellas’ mistake, see Ten, Medir el metro, 155.

  “For until this moment” and “I am not made”: Méchain to Delambre, 11 fructidor XII [29 August 1804], in Bigourdan, “Prolongation,” 400, 467.

  “As for the rest”: AAS Dossier Méchain, Méchain to Jaubert, 13 messidor XII [2 July 1804].

  Three days after: For a description of Méchain on the Sierra de Espadán, see Delambre, Notice historique de Méchain, 24. For the region around Espadán, see Townsend, Journey Through Spain, 3:296–98.

  “FRIDAY, SEPTEMBER 14”: Dezauche, “Journal,” [1794], in [Dezauche], “La dernière mission,” 159–68.

  The funeral was: For a copy of Méchain’s death certificate from the parish register of Castellón de la Plana, see AAS Dossier Méchain, “Dn. Pedro Méchain,” 14 September 1804.

  What eighteenth-century physicians: For a late eighteenth-century diagnosis of intermittent fever (malaria), see Vicq d’Azyr and Jeanrol, “Rapport . . . au sujet de l’épidémie qui a régné à Villeneuvelès-Avignon,” Histoire de la Société Royale de Médecine (1776): 213–25. For the most widely used treatise, translated into all the major languages of Europe and continuously in print since the middle of the eighteenth century, see James Lind, Essai sur les maladies des européens dans les pays chauds, Thion de la Chaume, ed. and trans. (Paris: Barrois, 1785). See also the compendia in J.-L. Alibert, Traité des fièvres pernicieuses, 3rd ed. (Paris: Crapelet, 1804). For the history of malaria in Spain, see Leonard Jan Bruce-Chwatt and Julian de Zulueta, The Rise and Fall of Malaria in Europe: A Historico-Epidemiological Study (Oxford: Oxford University Press, 1980), 123–28.

  In his final delirium: On Méchain’s obsession with his papers, see Delambre, Notice historique sur M. Méchain, 28.

  News of Méchain’s death: For the announcement in Paris, see ASPV 3 (16 vendémiaire XIII [8 October 1804]): 138.

  The rest of Méchain’s: On the sale of Méchain’s library, see BN Delta 49306, Catalogue des livres et instruments du feu M. P.-Fr.-And. Méchain, sale on 4 floréal XIII [24 April 1805] (Paris: Bleuet, XIII [1805]). On the penury of the Méchain family after his death, see AN F17 1541, Jaubert to Min. Int. [Champagny], 18 ventôse XIII [9 March 1805]. On Madame’s Méchain’s efforts to obtain a pension, see AN F17 1541, Madame Méchain to Min. Int. Champagny, received 3 nivôse XIII [24 December 1804]; Min. Int. to Madame Méchain, 11 ventôse XIII [2 March 1805]; Min. Int. “Rapport à Sa Majesté l’Empereur,” 24 pluviôse XIII [14 February 1805]; Napoleon, “décret ce qui suit . . . Méchain,” n.d. The final pension was 1500 francs per year, one third of which would revert to Méchain’s daughter upon her mother’s death.

  “far from his country”: AOP E2-21, Augustin Méchain, “Notice,” [1804–5].

  In a still briefer: For Lalande’s obituary, see Lalande, “Nécrologie,” Moniteur 22 (7 nivôse XIII [28 December 1804]): 78. See also Barón de la Puebla, “Nachtrag zu Méchains Biographie,” MC (1805): 367–69.

  “And never has”: Delambre, Notice historique sur M. Méchain, lue, le 5 messidor XIII [24 June 1805] (Paris: Baudouin, January 1806), 19.

  “Never did he consider” and “From this day”: Delambre, Notice historique sur M. Méchain, 30. Delambre did publish a few of Méchain’s observations found amid his papers; see ASPV 3 (22 pluviôse XIII [11 February 1805]): 180.

  It was a sincere: For the publication of the eulogy, see BA MS2038, Delambre to Baudouin, 21 January 1806.

  The publisher had been: For a contemporary account of the pressure on Delambre to complete his book manuscript, and the fact that although he had received the first batch of Méchain’s papers he
had yet to go through them, see UBL MS074, Delambre to Van Swinden, 10 ventôse XIII [1 March 1805]. Delambre himself says he did not have Méchain’s papers in time for Volume 1, in Delambre, Base, 2:v–x. For a retrospective account, see Delambre, Grandeur, 224. On the meaning of the meter, see Ludwig Wittgenstein, Philosophical Investigations, G. E. M. Anscombe, trans., 2nd ed. (Oxford: Blackwell, 1963), section 50. Also Saul Kripke, Naming and Necessity (Cambridge: Harvard University Press, 1972).

  ELEVEN: MÉCHAIN’S MISTAKE, DELAMBRE’S PEACE

  The fault, dear Brutus: William Shakespeare, Julius Caesar, Act 1, scene ii, The Riverside Shakespeare (Boston: Houghton Mifflin, 1974), 1108.

  “The historian”: Delambre, Histoire de l’astronomie moderne (Paris: Courcier, 1821), 1:xli. He is speaking of his treatment of Descartes; see below.

  “without the least omission”: Delambre, Rapport historique, 68.

  “Conquests will come”: KM, Delambre, Base, 1:title page. As it is not clear when Delambre presented the Base to Napoleon, it may well have been when all three volumes were published in 1810; see BA MS2038, Delambre to Baudouin, 21 January 1806. Delambre deliberately refrained from dedicating the Base to the Emperor to avoid the impression of kowtowing; see Delambre, “Lui-même.”

  “Loose pieces”: AOP E2-9, Delambre’s comments at end of Méchain’s notebook.

  In some cases: For Méchain’s alterations, see AOP E2-9, 23 January 1793. In one instance, Delambre could tell that the data had been recopied because of the way they were laid out on the page; yet Méchain had appended the times of the observations to the top and bottom of the page, something that served no purpose except to make the page appear to be original.

  “All the variants”: Delambre, in KM, Delambre, Base, 1:510. For Delambre’s notes on Méchain’s sections, see KM, Delambre, Base, 1:289-510. For Méchain’s “falsifications” at Saint-Pons, see p. 345. The many alterations at Carcassonne (sixteen series suppressed) shifted the final outcome by 1.91 seconds; see p. 374. Delambre notes a case in which Méchain presented data to the International Commission that had been altered by two full seconds without any plausible explanation; see p. 386. Delambre also made corrections for typographical errors and occasionally tweaked his own equations.