Mining > Mundus Subterraneous
Mundus Subterraneus (1665), first published in 1664, contains Athanasius Kircher's (1601 or 1602-1680) geological observations and speculations, including his model of a subterranean network of fire and suggestion that the tides are caused by seawater flowing in and out of internal oceans. Kircher's writing is more theoretical than the practical De re metallica and is aimed more exclusively at a scholarly audience.
