From Thomas Jefferson to Thomas Whitney, 13 June 1802
To Thomas Whitney
Washington June 13. 1802.
Sir
I observe in the European catalogues of Optical, Astronomical &c. Instruments, they advertize ‘Artificial horizons by parallel glasses and quicksilver to take double altitudes by, £1–16. sterl.’ I suppose it possible that this may be to supply the want of a good horizon at land and enable us to use Hadley’s quadrant here as well as at sea. should this be the case, and you happen to have one, or if you can procure one I shall be glad to recieve it by mr Claxton, and will have the price remitted to you as soon as known. mr Claxton took charge of a limb of the fixed machinery of the Quadrant, which had got broke on it’s passage, and which he was to desire you to repair. Accept my respects & best wishes.
Th: Jefferson
RC (Herbert R. Strauss, Chicago, Illinois, 1953); addressed: “Mr. Thomas Whitney Mathematical instrumt maker Philadelphia”; endorsed by Whitney. PrC (MoSHi: Jefferson Papers); endorsed by TJ in ink on verso. Enclosed in TJ to Thomas Claxton, 13 June.
Thomas Whitney (d. 1823) manufactured, repaired, and imported astronomical, surveying, and optical instruments in Philadelphia beginning about 1797. He was an English immigrant who learned his craft in “the first manufactories in London.” He also offered pilots’ charts and navigation books for sale and gave instruction in the use of sextants and other instruments. Prior to the departure of the Corps of Discovery in 1803 in search of a route to the Pacific, Meriwether Lewis obtained several instruments for the expedition’s use, including compasses of Whitney’s manufacture, from Whitney’s shop (Philadelphia Gazette, 12 May 1798, 29 Oct. 1801; Deborah Jean Warner, “Optics in Philadelphia during the Nineteenth Century,” APS, Proceedings, 129 [1985], 292; Domenic Vitiello, “Reading the Corps of Discovery Backwards: The Metropolitan Context of Lewis and Clark’s Expedition,” in The Shortest and Most Convenient Route: Lewis and Clark in Context, ed. Robert S. Cox [Philadelphia, 2004], 26–7; , 347).