1Robert Patterson to Thomas Jefferson, 30 November 1812 (Jefferson Papers)
Redheffer, Charles; perpetual-motion machine of [index entry]
2Enclosure: Drawing of Charles Redheffer’s Perpetual-Motion Machine, [ca. 30 November 1812] (Jefferson Papers)
Redheffer, Charles; perpetual-motion machine of [index entry]
3Thomas Jefferson to Robert Patterson, 27 December 1812 (Jefferson Papers)
Redheffer, Charles; perpetual-motion machine of [index entry]
4Robert Patterson to Thomas Jefferson, 12 January 1813 (Jefferson Papers)
Redheffer, Charles; perpetual-motion machine of [index entry]