Historian of pre-Christian art; developed the idea that prehistoric objects could be measured by periods of geologic time in which they were imbedded. Boucher de Perthes was appointed the director of the customhouse at Abbeville in 1825. Like many educated people in the nineteenth century, his hobby was archaeology. He spent his spare time digging in the nearby Somme valley. By 1837, his discoveries included flint hand axes and other tools lodged in the bones of mammals known to be extinct.