To [Pierre Delaunay?] des Landes8
Copy: Library of Congress
Passy, Nov. 23. 1779.
Not understanding well enough the french language and the technical Terms used in the Description of your Observatory, I cannot form, from the description such an Idea of its Situation and Circumstances, as might enable to me to Answer the Questions you propose to me. But as my Learned and Ingenious friend Mr. LeRoy, Member of the Academy of Sciences, is perfectly well acquainted with the Subject, I have put your Paper into his hands, and request the favour of him to give you the Information you desire. I have the honour to be Sir &c.
A M. Des Landes
8. It is tempting to assume that the copyist mistranscribed the name of BF’s astronomer friend Joseph-Jérôme le Français de Lalande, but the tone and content of the letter militate against that hypothesis. The style is too curt for a message to someone BF knew so well from the Lodge and the Académie des sciences. And why inform Lalande that J.-B. Le Roy was a member of the academy? A possible guess is that the recipient was Pierre Delauney Deslandes (1722–1803), director of the glass factory of St. Gobain, a man of wide scientific interests, friend of Lavoisier and Turgot, and a correspondent of the Académie des sciences since 1774: DBF.