Jefferson’s copy was sent to him by William Short in June, 1790, to whom the former wrote from New York on July 26: “ . . . I duly received the copy you were so kind as to send me of the Bishop of Autun’s proposition, on the subject of weights and measures. it happened to arrive in the moment I was about giving in to Congress a report on the same subject, which they had referred to me. in consequence of the Bishop of Autun’s proposition, I made an alteration in my report, substituting 45 ^o instead of 38 ^o, which I had at first proposed as a standard latitude. I* send you a copy of my report for the Bishop, and another for M. Condorcet, Secretary of the Academy of sciences. by taking the second pendulum or rod of the same latitude for the basis of our measures, it will at least furnish a common measure to which both our systems will refer, provided our experiments on the pendulum or rod of 45 ^o should yield exactly the same result with theirs . . .

" *sent by m( ^~ r) Barrett.”

On June 14, 1790, Jefferson wrote to David Rittenhouse a letter stating that he had that morning “recieved from m( ^~r) Short a proposition made by the Bishop of Autun to the National assembly of France”, in which he analyzed Talleyrand-Périgord’s work. See Jefferson’s Report . . . on . . . Weights, Measures and Coins , no. 3760 above.

No copy was seen for collation.

Jefferson’s copy was sent to him with a letter from Condorcet, which was bound in with the pamphlet. A copy of this letter is in the Jefferson Papers in the Library of Congress; it may be a genuine copy, or may be a translation. It reads as follows: “Letter from M. de Condorcet perpetual Secretary of the Academy of Sciences at Paris to M ^r. Jefferson, received July 19 ^th. 1791.

"I have the honor to transmit to you a copy of the Report made to the Academy of Sciences, relative to the determination of an unit of measure. You will therein perceive our reasons for renouncing the more simple idea of taking the length of the pendulum for the unit, and availing ourselves of the fortunate circumstance which placed within our reach the only meridian line of neither too great nor too small an extent, terminated by the sea at its two extremes which is cut by the forty fifth parallel of Latitude at about one third of its length.

"In consequence of a Decree of the National Assembly adopting the principles of the Report, the academy has formed five committees: the business of the first (consisting of Mess ^rs. Cassini, Mechain, and Le Gendre) is to make the astronomical observations and measure the triangles (particular circumstances having induced us to join these two Commissions) the second Commission entrusted (to Mess ^rs. Monge & Meusnier) is for the measurement of angles: a third (to Mess ^rs. de Provda & Coulomb) is to make observations on the pendulum: a fourth (to Mess ^rs. Lavoisier & the abbé Haüy) is to determine the weight of a given quantity of distilled water: and the fifth (to Mess ^rs. Tillet, Brisson, & Vandermonde) is to be employed in determining the relation of the ancient weights and measures with the toise and the pound. These Committees will begin their operations immediately, and I will take care to keep you informed of their proceedings herein.”

Jefferson acknowledged the receipt in a letter to Condorcet dated from Philadelphia, August 30, 1791: “ I am to acknolege the reciept of your favor on the subject of the element of measure adopted by France. candor obliges me to confess that it is not what I would have approved. it is liable to the inexactitude of mensura- ”