Pierre Simon de Laplace, the French astronomer and mathematician famous for his celestial mechanics and theory of probability, was born in Normandy. Upon coming to Paris, he attracted the attention of Jean Le Rond d'Alembert, who found him employment in the École Militaire. Here he taught mathematics to trainee artillery officers, among whom was Napoleon Bonaparte. When the revolutionary government established the École Polytechnique, Laplace was one of its founding professors. He served with distinction on many of the great committees of the French Academy of Sciences and of the government. He helped devise the meter, standardized weights and measures, and worked out an ingenious system of sampling to provide an economical and efficient census. The elegance of his mathematical work has yet to be rivaled, and his power of analysis is matched only by that of Isaac Newton and...