Chapter 4

James Hutton and the study of the rocks--His theory of the earth--His belief in volcanic cataclysms in raising and forming the continents--His famous paper before the Royal Society of Edinburgh, 1781---His conclusions that all strata of the earth have their origin at the bottom of the sea---His deduction that heated and expanded matter caused the elevation of land above the sea-level--Indifference at first shown this remarkable paper--Neptunists versus Plutonists--Scrope's classical work on volcanoes--Final acceptance of Hutton's explanation of the origin of granites--Lyell and uniformitarianism--Observations on the gradual elevation of the coast-lines of Sweden and Patagonia--Observations on the enormous amount of land erosion constantly taking place,--Agassiz and the glacial theory--Perraudin the chamois-hunter, and his explanation of perched bowlders--De Charpentier's acceptance of Perraudin's explanation--Agassiz's paper on his Alpine studies--His conclusion that the Alps were once covered with an ice-sheet--Final acceptance of the glacial theory--The geological ages--The work of Murchison and Sedgwick--Formation of the American continents--Past, present, and future.