Kircher envisioned the Earth as a sort of vast hot water tank, with icy water from the ocean pouring in at the North Pole in a great vortex, percolating southward through the Earth’s interior, heated by a Central Fire (provided by alchemical cosmic rays), and emerging on the surface again, comfy as bathwater and ready to go, at the South Pole—a system of heating and circulation he believed kept the oceans from either freezing or turning putrid. His drawings illustrating this system (including subterranean lakes and rivers) are probably the earliest attempt to show global patterns of ocean circulation. (Reprinted with permission of the Mineralogisches Institut, Universitaet Wurzburg Am Hubland, Wuerzburg, Germany)