Louis Poinsot was a French mathematician and physicist. Poinsot was the inventor of geometrical mechanics, showing how a system of forces acting on a rigid body could be resolved into a single force and a couple.

Baron Augustin-Louis Cauchy was a French mathematician, engineer, and physicist. He was one of the first to rigorously state and prove the key theorems of calculus, pioneered the field complex analysis, and the study of permutation groups in abstract algebra. Cauchy also contributed to a number of topics in mathematical physics, notably continuum mechanics.