William Smith started his career in a world where much was known of geological matters and, with the publication of Hutton's Theory of the Earth, knowledge was being tempered by understanding. His early training as a surveyor gave him the skills of accurate observation and recording together with a geographically wide experience that enabled him to recognize that strata could be ordered, and outcrops correlated, by the fossils that they contained. He first recorded this new concept in 1797 and used it to create the world's first geological map (of the area around Bath) in 1799 and the first geological map of England and Wales in 1815. The national map was not only geologically detailed and accurate but also showed collieries, mines, canals ...