Fossil Succession (William Smith, 1769-1839). Smith worked on canal projects as a civil engineer. Through his practical fieldwork he came to recognize that different sedimentary beds could be recognized by the different assemblages of fossils that were contained within them. He also recognized that each assemblage gave way to another as you moved vertically through a geologic column. This concept, that fossils succeed each other in a recognizable order throughout time enable geologists to "correlate" strata of the same age in different geographic areas.