Richard Foster Flint and Brian J. Skinner, Physical Geology, John Wiley and Sons, 1974
Suggested by Morgan Sherburne
In 1678 A German scholar, Athanasius Kircher, depicted the most advanced thinking of his day. Earth's interior was supposed to contain a giant, fiery inferno. The fires heated water that had seeped in from the ocean and gave rise to hot springs. Where tongues of fire came close to Earth's surface (lower right), they started volcanoes. (From Mundus Subterraneus, by Athanasius Kircher, 1678.)
