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I tender you my friendly and respectful salutations.
TO MR. DUNBAR.
Washington, May 25, 1805.
Dear Sir,—Your several letters, with the portions of your journals, forwarded at different times, have been duly received; and I am now putting the journal into the hands of a person properly qualified to extract the results of your observations, and the various interesting information contained among them, and bring them into such a compass as may be communicated to the Legislature. Not knowing whether you might not intend to make a map yourself, of the course of the river, he will defer that to the last part of his work, on the possibility that we may receive it from yourself. Your observations on the difficulty of transporting baggage from the head of the Red river to that of the Arkansas, with the dangers from the seceding Osages residing on the last river, have determined me to confine the ensuing mission to the ascent of the Red river to its source, and to descend the same river again, which will give an opportunity of better ascertaining that which, in truth, next to the Missouri, is the most interesting water of the Mississippi. You will accordingly receive instructions to this effect, from the Secretary of War. Dr. Hunter does not propose to take a part in this mission, and we suppose that Mr. George Davis, a deputy of Mr. Briggs, will be the fittest person to take the direction of the expedition, and Col. Freeman as an assistant, and successor, in case of accident, to the principal. Still, these propositions are submitted to your control, as being better acquainted with both characters. I write to Gov. Claiborne, to endeavor to get a passport from the Marquis of Casa-Calvo, for our party, as a protection from any Spaniards who may be fallen in with on the route. We offer to receive one or two persons, to be named by him, and subsisted by us into the party, as a proof that the expedition is merely scientific, and without any views to which Spain could take exception. The best protection against the Indians will be the authority to confer with them on the subject of commerce. Such conferences should be particularly held with the Arkansas and Panis, residing on the Red river, and everything possible be done to attach them to us affectionately. In the present state of things between Spain and us, we should spare nothing to secure the friendship of the Indians within reach of her. While Capt. Lewis' mission was preparing, as it was understood that his reliance for his longitudes must be on the lunar observations taken, as at sea, with the aid of a time-keeper, and I knew that a thousand accidents might happen to that in such a journey as his, and thus deprive us of the principal object of the expedition, to wit, the ascertaining the geography of that river, I set myself to consider whether in making observations at land, that furnishes no resource which may dispense with the time-keeper, so necessary at sea. It occurred to me that as we can always have a meridian at land, that would furnish what the want of it at sea obliges us to supply by the time-keeper. Supposing Capt. Lewis then furnished with a meridian, and having the requisite tables and nautical almanac with him,—first, he might find the right ascension of the moon, when on the meridian of Greenwich, on any given day; then find by observation when the moon should attain that right ascension (by the aid of a known star), and measure her distance in that moment from his meridian. This distance would be the difference of longitude between Greenwich and the place of observation. Or secondly, observe the moon's passage over his meridian, and her right ascension at that moment. See by the tables the time at Greenwich when she had that right ascension. That gives her distance from the meridian of Greenwich, when she was on his meridian. Or thirdly, observe the moon's distance from his meridian at any moment, and her right ascension at that moment; and find from the tables her distance from the meridian of Greenwich, when she had that right ascension, which will give the distance of the two meridians. This last process will he simplified by taking, for the moment of observation, that of an appulse of the moon and a known star, or when the moon and a known star are in the same vertical. I suggested this to Mr. Briggs, who considered it as correct and practicable, and proposed communicating it to the Philosophical Society; but I observed that it was too obvious not to have been thought of before, and supposed it had not been adopted in practice, because of no use at sea, where a meridian cannot be had, and where alone the nations of Europe had occasion for it. Before his confirmation of the idea, however, Capt. Lewis was gone. In conversation afterwards with Baron Humboldt, he observed that the idea was correct, but not new; that I would find it in the third volume of Delalande. I received two days ago the third and fourth volumes of Montuela's History of Mathematics, finished and edited by Delalande; and find, in fact, that Morin and Vanlangren, in the seventeenth century, proposed observations of the moon on the meridian, but it does not appear whether they meant to dispense with the time-keeper. But a meridian at sea being too impracticable, their idea was not pursued. The purpose of troubling you with these details, is to submit to your consideration and decision whether any use can be made of them advantageously in our future expeditions, and particularly that up the Red river.
Your letter on the current of the Mississippi, and paper on the same subject, corrected at once my doubts on your theory of the currents of that river. Constant employment in a very different line permits me to turn to philosophical subjects only when some circumstance forces them on my attention. No occurrence had called my mind to this subject, particularly since I had first been initiated into the original Torricellian doctrine of the velocities at different depths, being in the sub-duplicate ratio of the depths. And though Buat had given me his book while at Paris, your letter was the first occasion of my turning to it, and getting my mind set to rights to a certain degree. There is a subsequent work by Bernard, which is said to have furnished corrections and additions to Buat; but I have never seen it.
The work we are now doing is, I trust, done for posterity, in such a way that they need not repeat it. For this we are much indebted to you, not only for the labor and time you have devoted to it, but for the excellent method of which you have set the example, and which I hope will be the model to be followed by others. We shall delineate with correctness the great arteries of this great country. Those who come after us will extend the ramifications as they become acquainted with them, and fill up the canvas we begin. With my acknowledgments for your zealous aid in this business, accept my friendly salutations, and assurances of great esteem and respect.
TO DOCTOR SIBLEY.
Washington, May 27, 1805.
Dear Sir,—I have been some time a debtor for your letters of March 20th and September 2d, of the last year. A constant pressure of things which will not admit delay, prevents my acknowledging with punctuality the letters I receive, although I am not insensible to the value of the communications, and the favor done me in making them. To these acknowledgments I propose to add a solicitation of a literary kind, to which I am led by your position, favorable to this object, and by a persuasion that you are disposed to make to science those contributions which are within your convenience. The question whether the Indians of America have emigrated from another continent, is still undecided. Their vague and imperfect traditions can satisfy no mind on that subject. I have long considered their languages as the only remaining monument of connection with other nations, or the want of it, to which we can now have access. They will likewise show their connections with one another. Very early in life, therefore, I formed a vocabulary of such objects as, being present everywhere, would probably have a name in every language; and my course of life having given me opportunities of obtaining vocabularies of many Indian tribes, I have done so on my original plan, which though far from being perfect, has the valuable advantage of identity, of thus bringing the languages to the same points of comparison. A letter from you to General Dearborne, giving valuable information respecting the Indians west of the Mississippi and south of the Arkansas, presents a much longer list of tribes than I had expected; and the relations in which you stand with them, and the means of intercourse these will furnish, induce me to hope you will avail us of your means of collecting their languages for this purpose. I enclose you a number of my blank vocabularies, to lessen your trouble as much as I can. I observe you mention several tribes which, having an original language of their own, nevertheless have adopted some other, common to other tribes. But it is their original languages I wish to obtain. I am in hopes you will find persons situated among or near most of the tribes, who will take the trouble of filling up a vocabulary. No matter whether the orthography used be English, Spanish, French, or any other, provided it is stated what the orthography is. To save unnecessary trouble, I should observe that I already possess the vocabularies of the Attacapas and Chetimachas, and no others within the limits before mentioned. I have taken measures for obtaining those north of the Arcansa, and already possess most of the languages on this side the Mississippi. A similar work, but on a much greater scale, has been executed under the auspices of the late empress of Russia, as to the red nations of Asia, which, however, I have never seen. A comparison of our collection with that will probably decide the question of the sameness or difference of origin, although it will not decide which is the mother country, and which the colony. You will receive from Gen. Dearborne some important instructions with respect to the Indians. Nothing must be spared to convince them of the justice and liberality we are determined to use towards them, and to attach them to us indissolubly. Accept my apologies for the trouble I am giving you, with my salutations and assurances of respect.