1788-1859

Swiss civil engineer who demonstrated that a great ice sheet had once extended from the Central Alps across the Swiss plain to the Jura Mountains. He reasoned that alpine glaciers and large erratic boulders are remnants of this ice sheet and that moraines, piles of sediment deposited by glaciers, mark glacial advances and retreats. In 1836 he and Johann de Charpentier showed their evidence to Louis Agassiz, who further developed the idea of continental glaciation.