Thomas Jefferson Papers

To Thomas Jefferson from Andrew Ellicott, 26 May 1801

From Andrew Ellicott

Philadelphia May 26th. 1801

Dear Sir

I have enclosed three more sheets of my astronomical observations.—Pages 109, and 110, contain a critical examination of a meridian traced agreeably to one of the methods which I proposed some years ago in a small publication, with this difference, I had to take γ casiop. in the vertical above α ursæ minor. on account of our latitude being too far south to take it below.—Page 111 contains the errors of the clock, with its rate of going, near the mouth of Flint River, with 10 results of as many observations for determining the longitude, six from the eclipses of ♃trs. satellites, and four from lunar distances,—the mean results of the two methods agree within less than 4 geographical miles: a coincidence scarcely to be expected even at permanent observatories.—Page 115 contains the method used to connect our observatory with the confluence of the Chotohocha, and Flint rivers, a diagram answering to the references you will find annexed to the page.—The geographical position of the confluence of those important rivers, is now perhaps as accurately determined, as almost any spot within the U.S.—The observations I find will occupy 150 pages, and probably be all struck off by the last of next week.—

I feel anxious, for several reasons about the fate of this work, first, because I unfortunately have no person to share the responsibility with me,—secondly, being done by an American, and the apparatus principally made by Mr. Rittenhouse and myself, and thirdly to shew that my exertions, and services, for nearly four years in a bad climate, and constantly surrounded by difficulties, entitled me to a better fate than embarrassment and ruin.—My journals, correspondence, astronomical observations, and charts will account for every day I spent whilst absent.—

I have the honour to be with sincere esteem and friendship. your Hb: Servt.

Andw. Ellicott.

P.S. since writing the foregoing letter the printer has furnished me with another sheet of the observations, the 124th. page contains the errors of the clock, with its rate of going at Point Peter, which is at the mouth of the River St. Mary’s, with the results of 10 observations for the longitude, six from the eclipses of ♃trs. satellites, and four from lunar distances.—

The mean of the eclipses of ♃trs. } h { West from Greenwich
satellites gives for the longitude 5. 26. 15
The mean of the lunar distances } 5. 26. 26
gives for the longitude

The difference is less than 3 geographical miles!—The result of the observations for the latitude, will come on the next sheet.—

This will be handed to you by Govr. Sargent, who I presume is no stranger to you, or I should have written a letter of introduction by him.—Much has been said against his administration, but I am nevertheless for certain reasons, which I have detailed to Mr. Madison, inclined to think favourably of it.—


RC (DLC); Ellicott used astronomical symbols for the star Gamma Cassiopeia (“γ casiop.”), for the alpha (α) star of the constellation Ursa Minor (Polaris, the pole star), and for the planet Jupiter (“♃”); at foot of first page: “President U.S.”; endorsed by TJ as received 30 May and so recorded in SJL. Enclosure: see Ellicott to TJ, 16 May.

Small publication: Ellicott’s Several Methods by Which Meridional Lines May be Found with Ease and Accuracy, published in 1796 (Vol. 30:162n; Vol. 32:547–8, 549n).

Chotohocha: another name for the Apalachicola River (APS description begins American Philosophical Society description ends , Transactions, 5 [1802], 287).

Ellicott’s letter to Madison about Winthrop Sargent was dated 27 May. Confessing that he knew nothing of the particulars of Sargent’s administration of the Mississippi Territory, Ellicott decried the “faction” that opposed the governor (Terr. Papers description begins Clarence E. Carter and John Porter Bloom, eds., The Territorial Papers of the United States, Washington, D.C., 1934–75, 28 vols. description ends , 5:126–7; Madison, Papers, Sec. of State Ser. description begins J. C. A. Stagg, ed., The Papers of James Madison, Secretary of State Series, Charlottesville, 1986–, 8 vols. description ends , 1:233).

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