Lambert Adolphe Jacques Quetelet (1796-1874), Belgian astronomer, mathematician, statistician and sociologist. Quetelet received a doctorate in mathematics in 1819. Soon after he managed to convince government officials of the necessity of an astronomical observatory in Brussels, which was built in 1828. Quetelet went on to apply the new sciences of statistics and probability to criminology and the social sciences, becoming a leading figure in these fields. Perhaps his most famous legacy though is that of the body mass index (or Quetelet index), which remains the most commonly used raw material for obesity statistics. Illustration published in Acad. Royale de Belgique. Annuaire (1875).