George Poulett Scrope, an English geologist, was born Mar. 10, 1797. In the early 1820s, Scrope visited the mountainous region of south-central France, which included areas known as the Auvergne, the Velay, and the Vivarais. Fifty years earlier, French geologist Nicolas Demarest had revealed that the mountains of the Auvergne were actually extinct volcanos, and Scrope wanted to see for himself. He found that Desmarest was right–there was basalt everywhere, hundreds of feet of it in distinct layers, all apparently disgorged from volcanoes now long extinct. He published a book on the region in 1827, called Memoir on the Geology of Central France; it took five years to publish because of the elaborate folding hand-colored panoramic engravings that he included in the volume of plates. We see three of the plates here; the first shows the region of the Auvergne that includes the Puy de Dôme, the tallest mountain (and extinct volcano) in the region (see first and second images above). The second folding plate depicts an area to the east, in the Vivarais, near the city of Jaujac, where they are thick layers of basalt criss-crossing one another that were subsequently eroded by a river (images three, four, and five above are from this one plate). The third panorama shows an area near Le Puy en Velay, where a lone monastery sits atop a basalt puy or butte (sixth and seventh images).
Scrope came to conclude that the Auvergne, Velay, and Vivarais regions had formed from volcanic processes over a very long period of time, and his ideas on the immensity of geological time were taken up by Charles Lyell, when he put forward his principle of uniformitarianism in 1830. We displayed Scrope’s book in our 2004 exhibition, Vulcan’s Forge and Fingal’s Cave.
Dr. William B. Ashworth, Jr., Consultant for the History of Science, Linda Hall Library and Associate Professor, Department of History, University of Missouri-Kansas City