Fine example of Kircher's bizarre encyclopaedia of subterranean geography, incorporating the first printed map of Atlantis.

The work is one of the earliest works on speleology, one of the first to propose a fiery volcanic structure for the interior of the earth, and includes theories for weathering, and the water cycle. It also includes discussions of the location of the lost Island of Atlantis, alchemy, the existence of dragons and giants, and the spontaneous generation of animals from inert objects.

The Atlantis Myth
The first accounts of Atlantis appear in Plato's Socratic dialogue in two parts: 'Timaeus and Critias' (360BC).

At the beginning of 'Timaeus', Plato mentions Atlantis for the first time: "Then listen, Socrates, to a tale which, though strange, is certainly true, having been attested by Solon... For these histories tell of a mighty power... This power came forth out of the Atlantic Ocean, for in those days the Atlantic was navigable; and there was an island situated in front of the straits which are by you called the Pillars of Heracles; the island was larger than Libya and Asia put together... Now in this island of Atlantis there was a great and wonderful empire which had rule over the whole island and several others, and over parts of the continent, and, furthermore, the men of Atlantis had subjected the parts of Libya within the columns of Heracles as far as Egypt, and of Europe as far as Tyrrhenia..... But afterwards there occurred violent earthquakes and floods; and in a single day and night of misfortune all your warlike men in a body sank into the earth, and the island of Atlantis in like manner disappeared in the depths of the sea".

In 'Critias', Plato goes into greater detail about Atlantis's geography and wealth: "...they had such an amount of wealth as was never before
possessed by kings and potentates, and is not likely ever to be again... For
because of the greatness of their empire many things were brought to them from foreign countries, and the island itself provided most of what was required by them for the uses of life. In the first place, they dug out of the earth whatever was to be found there, solid as well as fusile... orichalcum
was dug out of the earth in many parts of the island, being more precious in those days than anything except gold. There was an abundance of wood...
there were a great number of elephants... there was provision for all other
sorts of animals... Also whatever fragrant things there now are in the earth,
whether roots, or herbage, or woods, or essences which distill from fruit and flower, grew and thrived in that land; also the fruit.. we call them all by the common name pulse, and the fruits having a hard rind... affording
drinks and meats and ointments, and good store of chestnuts and the like... that sacred island... brought forth fair and wondrous and in infinite
abundance. With such blessings the earth freely furnished them...".

Plato's account was barely disputed in the ancient world. Indeed, Hans Schindler Bellamy uncovered over 100 classical references to Atlantis in his 'The Atlantis Myth'. While discussion of the ill-fated island dropped off after the sixth century, two events in the fifteenth century reignited interest in this enigmatic land. The first was Marsilio Ficino's translation of Plato's work into Latin, and the second was Christopher Columbus's discovery of the New World. Suddenly, the world was far larger than had been previously thought, and the possibility of further lands awaiting discovery was both tantalizing and real.

The Mundus Subterraneus
"The basis and impetus for the 'Mundus subterraneus' was Kircher's visit to Sicily in 1637-38, where he witnessed an eruption of Aetna and Stromboli. He prefaced the work with his own narrative of the trip, including his spectacular descent into Vesuvius, ["I thought I beheld the habitation of Hell, wherein there seemed to be nothing besides the horrid phantasms and apparitions of Devils", He heard "horrible bellowings and roarings" and there was "an inexpressible stink"]. Upon his return to Italy. His observations of these volcanoes led him to conclude that the centre of the earth is a massive internal fire for which the volcanoes are mere safety valves. But the work is not solely geological. Kircher continues with fantastic speculations about the interior of the earth, its hidden lakes, its rivers of fire, and its strange inhabitants. Major topics include gravity, the moon, the sun, eclipses, ocean currents, subterranean waters and fires, meteorology, rivers and lakes, hydraulics, minerals and fossils, subterranean giants, beasts and demons, poisons, metallurgy and mining, alchemy, the universal seed and the generation of insects, herbs, astrological medicine, distillation, and fireworks" (Merrill).

Kircher proposed a theory likening the Earth to a living organism, with water flowing in and out. As his biographer, John Edward Fletcher, states "In medieval thought, the Earth had a soul and a body... The sea, with its tides, flowed into the body of the Earth and out again, like water in the gills of a fish". If the Earth had a body, Kircher reasoned, then it needed a skeleton to protect itself, and he figured mountain ranges could serve that purpose. For Earth's skeleton to be complete, certain submerged mountain systems had to be included, and there were spots along many meridians where it made sense to put an island. All that led Kircher to resurrect the myth of Atlantis as proof of his theory. In 1664, Kircher decided to finally put Atlantis on a map.