William Dunbar to Thomas Jefferson, November 9, 1804
Thomas Jefferson Papers, Library of Congress
William Dunbar relates the beginnings of his exploration of the Red River, including ventures into former Spanish territory. He also relates general scientific information of interest to Jefferson.
Post of Washita 9th. Novr. 1804
After a voyage of trouble and retardment we are at last arrived at this place: Doctor Hunter's boat constructed after his chinese model has proved to be an unprofitable Vessel, being extremely heavy & making bad head way against the Current; her rate of going is not one half of what it ought to be for an expedition of the nature on which we are engaged; we have made a great Sacrifice of time in getting to this post, & in order that we may retrieve as much as possible our past loss, we are now changing our boat for one which is handsomely formed for advancing against the Current, and is built flat & light, so as to draw as little water as possible, which probably will not exceed 12 inches, whereas our first bark exceeded double that depth; for the use of this boat we are obliged to pay 11/4 dols pr. day, but the rapidity with which we expect to advance will prove as ample compensation; having reason to hope that exclusive of the frequent detentions upon Shallows, rocks, gravel-bars &c. we shall
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now advance with double our former velocity. The Common reckoning makes this spot from the mouth of the red river about 80 leagues, some call it more, but by our measure by Log and time makes it only 196 miles & 256 perches. From hence to the hot Springs is computed to be 150 leagues, we shall hope to find this distance as much Shortened by our measurement as the first part of the Voyage; in which case we may possibly arrive near to our destination about the end of this month; we take a guide or Pilot here to whom we shall pay 1 dol: pr. day.
Hitherto we have not Seen any thing interesting which is worthy of being particularly communicated to you at this moment, altho' I have got to the 36th quarto page of my Journal exclusive of the Courses & distances of the river with astronomical observations; those I could have wished to have Copied & forwarded, but am affraid time will not permit; it has been so constantly cloudy here Since our Arival, that I have not been able to make a lunar observation for the determination of the Longitude, but I had a
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good meridian altitude of the Sun to fix the Latitude ; the Longitude may for the present by estimated with very little error at 92 west of Greenwich. The Latitudes of the most remarkable points of this river are as follows: Mouth of Red river Maps: John Mitchell (1755) Antoine-Simon Le Page du Pratz (1763) Aaron Arrowsmith (1811) Aaron Arrowsmith (1802) 31° 1'. Mouth of Black river Maps: John Mitchell (1755) Antoine-Simon Le Page du Pratz (1763) Thomas Hutchins (1778) Aaron Arrowsmith (1802) 31° 37'57". Post of Washita 32° 29'57". The situation of Fort Miro Maps: Aaron Arrowsmith (1811) is about 350 yards higher on the river (north) & appears to be the private property of the former Civil Commandant under the Spanish Government. We shall I hope soon be able to make Satisfactory lunar observations for the ascertainment of the Longitude if not at this place, in its neighbourhood; I have a most excellent instrument for this purpose, being a Circle of reflection Supported upon a pedestal, which last facilitates greatly correct observations on land; this is wanting to the Sextant brought by Doctor Hunter, we have been endeavouring to Supply the want by a wooden Support. The Doctor has never been in the habit of using instruments of that nature, otherwise his assistance in the lunar observation would be of great advantage, by taking the moon's altitude, at the
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same instant that the moon's distance from the Sun or Star; at present we must depend totaly upon calculation of the altitude of the two bodies regulated by the time kept by the Watch; probably a little practice will render us all a little more perfect.