Often people's paths through life take them full circle.
Simon Winchester, for example, received a degree in geology over 30 years ago — then immediately veered off into a career in journalism and publishing.
The circle was completed, however, with Winchester's second best seller: He chronicled the life of William Smith, who many consider the father of stratigraphy.
Winchester entertained the crowd of about 650 with the story of his career and how his book, The Map that Changed the World, came to be.
"AAPG is one of the organizations in the world that has consistently championed William Smith, who is now a hero of mine," he said. "Most of you know far more about geology, stratigraphy and William Smith than I could imagine knowing, and I wouldn't presume to talk to you about stratigraphy — so I will tell you about the making of the book."
Following the success of Winchester's The Professor and the Madman, his editor analyzed the book's success to learn why it captured the public's imagination.
"He determined it was a story about a hitherto obscure man who made a major contribution to human society," Winchester said. "The trajectory of his life had dramatic ups and downs — great things happened and terrible things happened, and the end of his life was marked by grotesque bodily mutilation."
The editor said Winchester should find someone else who fit this criteria.
"I remembered that my tutor at Oxford once told me that one of the key figures in early geology was William Smith — that he was one of the great unsung heroes of the science," Winchester said.
Winchester looked Smith up in an old Encyclopaedia Britannica — and what he found was intriguing.
"It said 'Smith, William. Maker of first geologic map in world history.' Then came a series of sentences that increasingly whetted my appetite. His map was plagiarized, he became bankrupt, he went to debtor's prison, and his wife went mad and became a nymphomaniac.
"I knew I had a potential winner," he said to audience laughter.
The author began his research by contacting his old tutor at Oxford, who assisted with the research and was critical to the completion of the book.
"Smith was orphaned at a young age and lived with his aunt and uncle, who ran a dairy," Winchester said. "From that beginning he developed a fascination for the earth and collected fossils his entire life. He was one of the first true field geologists, which was his strength."
As an adult Smith became a surveyor, and while surveying canal construction he realized rocks are arranged in layers and it was likely that the rocks on top were younger than the rocks deeper in the earth.
"He observed that certain rocks contained certain fossils, and if you saw that same rock with that same fossil in different places all over England, then it was likely it was laid down everywhere," he said. "By looking at the rocks above the surface and how they dip into and out of the earth he could do something that had never been done before — he could make a map of subsurface rocks over the British Isles."
In 1815 Smith produced what is in effect the first proper national geological map in the world, which hangs today at The Geological Society headquarters in London.
"This map is quite extraordinary," he said. "If you compare Smith's map with a contemporary map made by thousands of highly paid, I assume, geologists, it is extraordinary how accurate this map produced by one penniless man in 1815 is in so many ways."