1Thomas Jefferson to John Wayles Eppes, 6 March 1817 (Jefferson Papers)
scientific instruments; sundials [index entry]
2Thomas Jefferson’s Instructions for Setting a Sundial, [ca. 6 March 1817] (Jefferson Papers)
scientific instruments; sundials [index entry]
3Thomas Jefferson to Benjamin Henry Latrobe, 12 June 1817 (Jefferson Papers)
scientific instruments; sundials [index entry]