Zahn was a gifted scholar and polymath active in Germany at the end of the seventeenth century. A Canon of the Premonstratensian Order, he studied mathematics, natural history, anatomy and geography; however, he is most famous for his studies in optics, a field in which he is renowned as a pioneer in the use of the Camera Obscura. He adapted it into a portable instrument and theoretically developed it into the equivalent of what would practically become a nineteenth century camera.



Apart from his study in optics, he was also fascinated by the natural world and among his many publications, in 1696 he issued a work entitled "Mundus Mirabilis" or the "Miraculous World" attempting to explain various natural and astronomical phenomena. Many of his explanations and theories were scientifically dubious and of questionable value but the work contains a series of fine engravings, illustrating his ideas, including this one.



This map is Zahn's version of an earlier map by Athanasius Kircher, illustrating a theory that all of the world's oceans and seas were connected through one vast underground ocean and that multiple deep water trenches and enormous shafts acted as water conduits, resulting in currents and tides experienced sailors and coastal dwellers alike.

This map attempts to chart the currents and mark the deep trenches and shafts on the ocean floor. Geographically, the model of the earth is greatly antiquated and with only detail of natural phenomena such as rivers, lakes and volcanoes. No effort is made to portray accuracy on the continental outlines and the nomenclature is vast and sweeping, only serving to identify continents or regions. The map also includes two features which first appeared in the later sixteenth century but were beginning to lose their credibility when Kircher's map was first issued in 1665: one was the vast unknown Great Southern Land and the other was a firm cartographic delineation of the Northwest and Northeast Passages.



Instead the map concentrates on showing sweeping currents over the oceans, attempting to show and chart their course over the globe. The concept of ocean currents is not new; this phenomenon had been reported by mariners for centuries but the attempt to map them and the explanation for their existence was novel. Two more features add to the fantastical nature of this map: one is the placement of a series of "Abyssos" or deep trenches on the ocean floor. Again, the sources for the placement of these must be questioned. Finally, Zahn also theorises about a series of underwater tunnels between the Black Sea and the Caspian Sea; the Caspian Sea and the Persian Gulf; and presciently, between the Mediterranean and the Red Sea. This may have been an attempt to explain vast inland bodies of water such as the Caspian Sea. The map also marks several volcanoes, including one in the Pacific Ocean.



One feature which Zahn does add to Kircher's map is a very large decorative border and title. Whereas the original map was a sparse if fantastical document, this item features a raised title within a floral border held by putti and supported on a stone surface. A narrower, lower border gives the impression that the map is part of a panel or stone tablet.



While the resulting map may seem fantastical and possibly a little ridiculous now, the ambition of the concept of attempting to map the currents of the oceans, explain the lack of tides on enclosed seas, record features of the ocean floor and possibly link them all together, was vast. This, in combination with the superlative engraving which enables these esoteric ideas to be illustrated so graphically makes this one of the most attractive and interesting early "curiosity" maps.

[Shirley 583] [WLD3443]