Winchester provides several maps and illustrations to assist the reader, as well as some nice drawings of various buildings that Smith lived in and a variety of ammonites, purely for the reader's pleasure. Winchester also provides a simplified Time Scale, a Glossary of Geological Terms, and a list of his Sources and Recommended Reading (with an asterisk by titles which will appeal to the general reader). All in all, I found The Map That Changed the World to be a highly readable and enjoyable book for both the scientist and the lay reader about a subject that is often considered quite dull.
Smith's critics may comment that he got extremely lucky. The layers of rock that he studied had a uniform dip, and their outcrops varied in interesting and obvious ways, so that it was easy to recognize how the rocks changed. He was also not the first to comment on the changing layers of rocks. What differentiates Smith from others of the time was that not only did he comment on these differences, he was able to assimilate what he saw and to make further inferences from these observations. When one considers how little was known about geology at the time, the contributions that Smith made to the science are quite remarkable.
