1Thomas Jefferson to Isaac Briggs, 17 April 1816 (Jefferson Papers)
Greenwich Observatory, England; and prime meridian [index entry]
2Thomas Jefferson to Bartholomew Fuller, 17 December 1819 (Jefferson Papers)
Greenwich Observatory, England; and prime meridian [index entry]
3William Lambert to Thomas Jefferson, 24 July 1810 (Jefferson Papers)
Greenwich Observatory, England; and prime meridian [index entry]
4William Lambert to Thomas Jefferson, 5 December 1809 (Jefferson Papers)
Greenwich Observatory, England; and prime meridian [index entry]
5William Lambert to Thomas Jefferson, 19 April 1810 (Jefferson Papers)
Greenwich Observatory, England; and prime meridian [index entry]
6William Lambert to Thomas Jefferson, 23 July 1809 (Jefferson Papers)
Greenwich Observatory, England; and prime meridian [index entry]
7William Lambert to Thomas Jefferson, 17 September 1809 (Jefferson Papers)
Greenwich Observatory, England; and prime meridian [index entry]
8William Lambert to Thomas Jefferson, 13 June 1809 (Jefferson Papers)
Greenwich Observatory, England; and prime meridian [index entry]
9William Lambert to Thomas Jefferson, 18 March 1822 (Jefferson Papers)
Greenwich Observatory, England; and prime meridian [index entry]
10William Lambert to Thomas Jefferson, 4 September 1809 (Jefferson Papers)
Greenwich Observatory, England; and prime meridian [index entry]