Used with
permission of Maiken Naylor, University at Buffalo, Buffalo, NY, USA,
http://ublib.buffalo.edu/libraries/units/sel/exhibits/stamps
Andre Marie Ampere (1775-1836) was inspired by the work of Oersted to study the interactions between current-carrying wires, and derived a mathematical formula describing this force. He devised the right-hand rule to describe current-flow. The unit of current, Ampere, is named after him.