1Thomas Jefferson’s Calculations of Latitudes of the Sharp Peak of Otter and Natural Bridge, 18 September–10 November … (Jefferson Papers)
sextant; TJ uses [index entry]
2Thomas Jefferson’s Field Notes and Calculations of Altitude of the Peaks of Otter, [10–ca. 17 November 1815] (Jefferson Papers)
sextant; TJ uses [index entry]
3Thomas Jefferson’s Observations for Calculating the Latitude of Monticello, 30 January–4 February 1816 (Jefferson Papers)
sextant; TJ uses [index entry]
4Thomas Jefferson to George Wyche, 10 November 1818 (Jefferson Papers)
sextant; TJ uses [index entry]