1736-1813

French-Italian Mathematician and Astronomer

Comte Joseph-Louis Lagrange ranks among the most important eighteenth-century Continental mathematicians. His best-known feat is the establishment of the metric standard, but this accomplishment came only after a number of other achievements, including contributions to algebra and number theory. Lagrange paved the way for modern mechanics by helping to establish a link between solid and fluid forms and he invented the calculus of variations when he was just 19 years old.

Born in Turin, Italy, on January 25, 1736, Lagrange was the son of aristocrats. His father served as treasurer of war in Sardinia and his mother came from a wealthy Italian family. Although Joseph-Louis was their eleventh and last child, he was the only one to survive childhood.

Initially, Lagrange showed little interest in mathematics, but, after reading an essay on calculus by Sir Edmond Halley (1656-1742), the course of his...