Auguste Bravais

Auguste Bravais (1811 to 1863) was a French physicist and naval officer, born in Annonay, who is remembered chiefly for his work in crystallography. In 1848 he showed that there are exactly fourteen distinct ways of arranging lattice points in three dimensional space, correcting an earlier scheme of fifteen by Frankenheim; these are now called the Bravais lattices. He also formulated the Bravais law on the faces of crystals. His wider mathematical work includes a 1844 paper on the statistical concept of correlation, in which he reached a definition of the product-moment correlation coefficient before Karl Pearson, and a 1846 paper on the probability of errors of a point. He studied at the Ecole Polytechnique alongside Evariste Galois, taught applied mathematics for astronomy at Lyon from 1840, held the chair of physics at the Ecole Polytechnique from 1845 to 1856, and joined the French Academy of Sciences in 1854. He also investigated magnetism, meteorology, geobotany and phyllotaxis, and tested the effect of the Earth's rotation on a conical pendulum.