Andre-Marie Ampere, French physicist and mathematician, 1825.
© Science Museum / Science & Society Picture Library
Engraving by Ambroise Tardieu, from the 'Dictionnaire des Sciences Naturelles' (1816-1830). Ampere (1775-1836) established the laws and principles which related magnetism and electricity to each other, and became Profesor of Physics and Chemistry at Bourg in 1801 and Profesor of Mathematics in the Ecole Polytechnique in Paris in 1809. He was celebrated for his contributions to electrodynamics, including his mathematical theory describing investigations into the forces exerted on each other by current- carrying conductors, and the properties of a solenoid. In 1881, 'ampere' was used to replace the term 'weber' as the unit of current.