Am·père \äⁿ-per\ , André Marie (1775–1836), French physicist. Ampère is credited with founding, naming, and developing the science of electrodynamics. He was the formulator of two laws in electromagnetism relating magnetic fields to electric currents. The first person to develop techniques for measuring electricity, he invented an instrument that was a forerunner of the galvanometer. In 1881 at the suggestion of Sir Charles Bright, an international congress on electricity adopted ampere as a term for the standard unit of electric current.