Mechanical calculator developed by Pascal. Blaise Pascal (June 19, 1623 - August 19, 1662) was a French mathematician, physicist, inventor, philosopher and child prodigy. He made important contributions to the study of fluids, and clarified the concepts of pressure and vacuum. While still a teenager, he started some pioneering work on calculating machines, and after three years of effort he invented the mechanical calculator. He wrote a significant treatise on the subject of projective geometry at the age of 16, and later corresponded with Pierre de Fermat on probability theory, strongly influencing the development of modern economics and social science. His Trait矇 du triangle arithm矇tique (Treatise on the Arithmetical Triangle) of 1653 described a convenient tabular presentation for binomial coefficients, now called Pascal's triangle. Always poor in helath he died in 1662 two months after his 39th birthday. An autopsy revealed grave problems with his stomach and other organs of his abdomen, along with damage to his brain.