Thomas Jefferson Papers

To Thomas Jefferson from Condorcet, [ca. 3 May 1791]

From Condorcet

[Paris, ca. 3 May 1791.] He encloses a copy of a report made to the Academy of Sciences on the determination of a unit of measure. TJ will perceive therein their reasons for rejecting the more simple idea of taking the length of the pendulum for the unit and availing themselves instead of the fortunate circumstance which placed within their reach the only meridian line of neither too great nor too small an extent, terminated by the sea at its two extremes and intersected by the 45° of latitude at about one-third of its length.

As a result of the decree of the National Assembly adopting the principles of the report, the Academy has created five committees. The first, consisting of Messrs. Cassini, Méchain, and Le Gendre, is to make the astronomical observations and measure the triangles. The second, Messrs. Monge and Meusnier, is to measure the angles. (Particular circumstances have induced him to associate himself with these two committees.) A third, Messrs. Borda and Coulomb, is to make observations on the pendulum. A fourth, Messrs. Lavoisier and Abbé Hauy, is to determine the weight of a given quantity of distilled water. And the fifth, Messrs. Tillet, Brisson, and Vandermonde, is to determine the relation of the ancient weights and measures to the toise and the pound. These committees are to begin their operations immediately. Condorcet will keep TJ informed of the results.

He offers thanks for the two works TJ was kind enough to send him. “They will instruct us in all that is needed for the success of our common aims. You have provided good proofs of the results. Permit me to count myself among those who will share them and accept the assurance of my respect.”1

RC (NNP); undated but written on either 2 or 3 May 1791 (Short’s letters of these dates refer to it first as promised and then as enclosed); endorsed by TJ as received on 19 July 1791 and so recorded in SJL. Tr (DLC); in George Taylor’s hand; at head of text: “Letter from M. de Condorcet perpetual Secretary of the academy of Sciences at Paris to Mr. Jefferson, received 19 July 1791.” The English translation in Tr omits the final paragraph. RC translated by the Editors.

Philip Freneau had not yet become translator for the Department of State when TJ received the above letter and its enclosed Rapport (printed below). But it is clear beyond doubt that the translation of both documents employed by the clerk of the Department of State in making the copies presented here was prepared by TJ himself and was very likely in the form of a rough draft. This is proved beyond question by the use of “it’s” for the possessive, by the beginning of some sentences with a lower case letter, by clerical errors made in the texts prepared by the copyist, by interpolations of clarifying phrases not in the original, and above all by the scrupulous accuracy, conciseness of expression, and translation so smooth and unmistakable in style that it does not appear to be such. Freneau, as shown by documents translated by him, could not conceal the hand of the translator even in subjects less scientific and technical than the principles of metrology. But TJ, in the act of converting French into English from the execrable handwriting of Condorcet as well as from the philosophical expressions of the Rapport, revealed his own profound knowledge of the subject—and, in so doing, exposed himself as one who executed the (missing) translation employed by the copyist. He also did so in the exclusion from the final paragraph of Condorcet’s letter of the complimentary allusion to his own classic Report on Weights and Measures.

This omission, together with the nature of the captions given to Condorcet’s letter and the Rapport as translated, suggest that TJ caused a departmental clerk to transcribe both documents because he contemplated releasing the texts to the press. He may also have thought thereby to make them available to Rittenhouse or to members of the American Philosophical Society. The originals were not presented to the Society and no copy of the translations has been found in contemporary newspapers. If TJ did not in fact communicate to the public the translations he had so laboriously prepared, the reason for withholding them could not have arisen from any lack of interest in the subject. His own hope for a universal and decimalized system of weights, measures, and coinage based on a unit of measure accessible to all nations was one he pursued all his life (see Editorial Note and group of documents on his Report on Weights and Measures, 4 July 1790). The reason is rather to be sought in the nature of the Academy of Sciences’ Rapport.

That document was submitted to the National Assembly on 26 Mch. 1791 as one consonant with the stipulations in the decree of the previous year on the report prepared by the Bishop of Autun: that, to achieve uniformity of weights and measures, a natural and invariable unit of measure should be fixed; that the only means of extending this system to other nations would be to get them to agree to the same unit; and that, in choosing it, nothing of an arbitrary nature should be permitted nor the particular situation of any people on the globe considered. The unit proposed by Talleyrand was the pendulum vibrating seconds at 45° latitude. TJ received news of Talleyrand’s proposal and of the National Assembly’s decree just as he was completing his own Report to Congress. He welcomed the choice of latitude 45° as the standard and immediately accepted it in substitution for his own choice of latitude 38°. He did so in the hope that this would result in a common measure on which the systems of both nations would be based (TJ to Short, 26 July 1790). In his letter submitting the Rapport of the Academy of Sciences to the National Assembly, Condorcet not only asserted that it met the stipulations of the previous year; he also claimed that the spirit of enlightenment and the progress of fraternity among all peoples was its object: “The operation which the Academy proposes is the greatest ever undertaken, and it can only bring honor to the nation which will execute it. The Academy … desires, in a word, that if the principles and details of this operation could pass alone to posterity, it would be impossible to tell by what nation it had been ordered or executed. The establishment of uniformity of measures is of such great utility and importance that it should be acceptable to all peoples… . The Academy feels that it must embrace the views of all men and all centuries” (Condorcet to the President of the National Assembly, undated; translation by the Editors from Procès-Verbal, 26 Mch. 1791, p. 12–14).

Despite the grand sentiments, the recommendations of the Academy of Sciences represented a retreat from those advanced by Talleyrand a year earlier. TJ thoroughly disapproved the plan, found it “uncatholic,” and, with blunt candor, gave his opinion to Condorcet: “I would rather have seen you depart from your Catholicism in religion than in your Philosophy” (TJ to Condorcet, 30 Aug. 1791). His obvious disappointment at this turn of events would seem to have provided sufficient reason for withholding Condorcet’s letter and the report of the Academy of Sciences from the public.

1This paragraph is omitted in TJ’s translation.

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