1Thomas Jefferson to Bartholomew Fuller, 17 December 1819 (Jefferson Papers)
Borda’s circle (surveying instrument) [index entry]
2Thomas Jefferson to Fernagus De Gelone, 7 March 1817 (Jefferson Papers)
Borda’s circle (surveying instrument) [index entry]
3Fernagus De Gelone to Thomas Jefferson, 15 March 1817 (Jefferson Papers)
Borda’s circle (surveying instrument) [index entry]