Complex sentence: He was one of the first Europeans to enunciate the correct theory of the origin of fossils and his practical application of Alexandrian theoretical works on hydraulics to the social issue of delivering public water to cities, were far in advance of the general knowledge of his time.
Split into simpler sentences: He was one of the first Europeans to enunciate theory consistent with today's understandings of the origin of fossils. That and his practical application of Alexandrian theoretical works on hydraulics to the social issue of delivering public water to cities, were far in advance of the general knowledge of his time.