1Thomas Jefferson to Henry A. S. Dearborn, 15 November 1811 (Jefferson Papers)
Monticello (TJ’s estate); latitude of [index entry]
2Thomas Jefferson’s Notes on the Latitude of Willis’s Mountain, [ca. 19 December 1811] (Jefferson Papers)
Monticello (TJ’s estate); latitude of [index entry]
3William Lambert to Thomas Jefferson, 8 January 1812 (Jefferson Papers)
Monticello (TJ’s estate).; latitude of [index entry]
4Thomas Jefferson’s Observations at Monticello Related to Calculation of Latitude, 11 October 1815–31 January 1816 (Jefferson Papers)
Monticello (TJ’s estate); latitude of [index entry]
5Thomas Jefferson’s Observations for Calculating the Latitude of Monticello, 30 January–4 February 1816 (Jefferson Papers)
Monticello (TJ’s estate); latitude of [index entry]