Emporium too, for May 1812, and August 1813, may offer something. The reports of the Committees of Parliament of 1758-9, I think you will find in Postlethwaite's Dictionary, which is also in the library, chapter 20, No. 10. That of Mechain and Delambre I have not, nor do I know who has it. I have lately seen a book which your office ought to possess, if it has it not already, entitled "_Memoire sur la Louisiane_, par M. le Comte de Vergennes, 8vo, Paris, chez Lepetit, Jeune, 1802." It contains more in detail the proofs of the extent of Louisiana as far as the Rio Grande than I have ever before seen, and its author gives it authenticity. It has been executed with great industry and research into the French records. This reminds me of a MS. which Governor Claiborne found in a private family in Louisiana, being a journal kept (I forget by whom, but) by a confidential officer of the government, proving exactly by what connivance between the agents of the _compagnie d'occident_ and the Spaniards these last smuggled settlements into Louisiana as far as Assinais, Adais, &c., for the purpose of covering the contraband trade of the company. Claiborne being afraid to trust the original by mail without keeping a copy, sent it on. It arrived safe, and was deposited in the office of State. He then sent me the copy on the destruction of the office at Washington by the British, apprehending the original might be involved in that destruction. I sent the copy to Colonel Monroe, then Secretary of State, with a request to return it if the original was safe, and to keep it if not. I have heard no more of it; but will now request of you to have search made for the original, and if safe, to return me the copy. I propose to deposit it with the historical committee of the Philosophical Society at Philadelphia, for safe keeping. I have no use nor wish for such a thing myself, but think it will be safer in two deposits than one. My recommendation to Colonel Monroe, was to have it printed. I have barely left myself room to express my satisfaction at your call to the important office you hold, and to tender you the assurance of my great esteem and respect. FOOTNOTE: [1] If conforming to this desire of other nations, we adopt the second pendulum, 3/10 of that for our foot will be the same as ⅕ or, 2/10 of the second rod, because that rod is to the pendulum as 3 to 2. This would make our foot ¼ inch less than the present one. TO MR. DUPONCEAU. MONTICELLO, November 7, 1817.