This is Happel's rendition of Athanasius Kircher's theory that the oceans of the world were all connected through a series of undersea rifts and tunnels which led to a vast underground ocean. These rifts were the explanation for ocean currents which had been noted since antiquity. Geographically, it has been updated since Kircher's map, especially in the northern regions, where Happel adds a vague though vast landmass called Greenland near North America while a huge peninsula has been added to the northern coast of Asia with Happel ascribing to the theory that Nova Zembla was a peninsula. There are no political borders and names are applied to huge regions such as "California" for western North America and Tartary for northern China, Mongolia and Central Asia. Happel also follows Kircher in showing the Caspian Sea connected with a huge undersea tunnel to the Black Sea; the same applying to the Caspian Sea and the Persian Gulf; and more presciently, the Mediterranean and the Red Sea under the Suez region. The sea bottom is also liberally sprinkled with a series of shafts leading down to Kircher's mythical underground ocean.

The engraving is very much German in style, resembling the map of Canon Johan Zahn, who also produced a version of Kircher's map postulating this theory. The swirls within the seas represent the currents, small volcanoes with erupting calderas show their activity.

While its conclusion may have been fantastical, it is still a very early example of a map trying to reconcile a known natural feature with a possible theory.

A rare and unusual example of early thematic cartography focusing on the natural world.

Shirley 468. [WLD3481]