Thomas Jefferson Papers

Robert Patterson to Thomas Jefferson, 12 March 1811

From Robert Patterson

Philada March 12th 1811


Agreeably to your desire I send herewith Garnetts’ Nautical Almanacs for the years 11. & 12—& shall not fail, life remaining, to forward those for succeeding years as soon as published.

I have lately added to the common artificial horizon, (the polished plane surface adjusted by a spirit-level) a very simple appendage, by the aid of which any altitude of the sun &c may be taken, on land, from 0 to 90°, either by the common octant or sextant, with the utmost ease & accuracy—a desideratum, so far as I know, hitherto unattained, in the use of this valuable instrument.

Instead of giving you a description of this apparatus, I request you will permit me to send you one, with directions for its use. It is no larger than a moderate sized snuff-box. By what conveyance can I forward it?—

I remain, sir, with perfect respect & esteem Your obedt servt

Rt Patterson

RC (MHi); endorsed by TJ as received 17 Mar. 1811 and so recorded in SJL. Enclosures: John Garnett, The Nautical Almanac and Astronomical Ephemeris (New Brunswick, 1803–13; Sowerby, description begins E. Millicent Sowerby, comp., Catalogue of the Library of Thomas Jefferson, 1952–59, 5 vols. description ends no. 3810), editions for 1811 and 1812.

Index Entries

  • Garnett, John; Nautical Almanac and Astronomical Ephemeris search
  • Jefferson, Thomas; Books & Library; works sent to search
  • navigational instruments search
  • Patterson, Robert; and artificial horizon search
  • Patterson, Robert; and Nautical Almanac search
  • Patterson, Robert; letters from search
  • scientific instruments; navigational search
  • sun; altitude of search
  • surveying; and artificial horizon search
  • The Nautical Almanac and Astronomical Ephemeris (J. Garnett); and R. Patterson search