I have been recurring to your pamphlet (which I borrowed for that purpose) for the times at which the inundations begin and end in the Missouri, Missisipi, Illinois, Ohio, Wabache, but I do not find it mentioned there. Will you be so kind as to give me as accurate an account of these times as you can? Does the Tanissee overflow periodically? I suppose not. Will you give me leave to correct an error in your pamphlet page 13. where you say that the country extending from Fort Pitt to the Missisipi and on both sides watered by the Ohio and it’s branches contains at least a million of square miles. I think the Ohio in all it’s parts and branches cannot water more than the fourth of that. Count the degrees in your map into which it pushes it’s branches. You will find them not quite 80, but suppose them made 80 by the branch of the Tanissee which heads in S. Carola. A degree in the middle of this space would contain about 3000, or 3100 square miles and of course 80 would contain about 250,000. I think the whole United states reduced to a square would not be more than one of 900 miles each way and of course that the whole U.S. do not contain a million of square miles. Excuse my freedom. I think this an error in your pamphlet and would wish to know from you whether I see it wrong. I am with much esteem Sir Your most obedt. servt