Your letter of Dec. 17. did not get to my hands till Feb. 11. I did not answer it immediately, because I was about communicating to Congress the information we had collected as to Louisiana which I thought would be immediately printed, & I wished at the same time to send you a copy of it. the printer however has taken till this time to do his duty. I send you a copy, & with the more justice as you have contributed so much towards it yourself.

Immediately on the receipt of your letter I asked information from mr Gallatin, on your account, as well as on that of another person who had applied to me about the same time whether the duties could be dispensed with on mathematical instruments, books &c. I inclose you his answer by which you will percieve that the law has given no such discretionary power.

Whether our party had better go up the Red river or the Arcansa first you are best able to judge, who are nearer & better acquainted with the circumstances which must decide. we would rather have had the Red river first surveyed; but the difference is not important. your proposition to ascertain interesting points of the alluvial country is too desireable not to be accepted, and the Secretary at War sends orders accordingly to the commanding officer at Fort Adams. as soon as we shall have actual surveys of the Misipi, Missouri, Arcansa & Red river we propose to have an accurate map made, towards which what you propose will be a valuable contribution. I am endeavoring to get through Congress an allowance for mr Briggs’s services on the road to N. Orleans. as soon as that is accomplished I meant to write to him. in the mean time be so good as to inform him that my personal knolege of him furnishes an evidence of his integrity too firm to be shaken by the maneuvres practised against him. accept my friendly salutations & assurances of great esteem & respect.