In my article "Dating Fossils I: Relative Dating" I discussed how paleontologists are able to determine the age of fossils by where they lie in the stratigraphic column; this is another basic scientific principle that most people come to realize early in their scientific education. Two hundred years ago, however, this was not the case. It took the surveys and study of an extraordinary man, William Smith, to recognize a fact that we take for granted today.
Simon Winchester, author of The Professor and the Madman (another book that I highly recommend), has written The Map That Changed the World: William Smith and the Birth of Modern Geology, a book that everyone with an interest in geology will find fascinating.
William Smith was born on March 23, 1769, in the hamlet of Churchill in Oxfordshire, the eldest child of the local blacksmith, John Smith. After the death of John Smith, William, his two brothers and his sister were all sent to live with an aunt and uncle who lived in the area as well. William's aunt was a dairymaid who operated the butter weighing scales. At that time, rather than using artificially made weights, it was the custom for the dairymaids to use a type of "stone" commonly found in the area. These "stones" were all of the same approximate size and conveniently weighed right at a pound each. Interestingly, they were of a rounded and flattened shape, sort of like a bun, and were commonly called "Chedworth Buns."
They also had strange markings on their topsides, sort of like a star. Most people of the time thought little of the Oxfordshire pound stones, but young William found them to be very interesting.
Today these Chedworth Buns are easily recognized as being the fossilized remains of echinoderms, or sea urchins, which can be found living on the English beaches. During the late eighteenth century, however, the idea of fossilization was unknown, and the idea of extinction of species was unthinkable, due to the religious strictures adopted by the Church at that time. Dr. James Hutton would not publish The Theory of the Earth until 1795, Sir Richard Owen would not name the Dinosauria until 1842 and Charles Darwin would not publish The Origin of Species until 1859.
