Inventio Fortunata - Influence On Maps

Influence On Maps

It is evident that the author of Inventio, if he actually travelled to the far north, did not actually reach the North Pole, which in no way resembles the description found in the book. However, it is likely that the author was speculating as to the source of the powerful magnetic force that underlies the functioning of the compass.

The concept of the pole as a magnetic mountain goes back at least to Roman times, but the author of Inventio Fortunata added other features to the picture as well as measurements. Whether or not the Inventio is the source of the medieval concept of the North Pole as a magnetic mountain surrounded by a circular continent divided by four powerful rivers, maps as early as Martin Behaim's 1492 globe depict the region in this way.

Johannes Ruysch's Universalior cogniti orbis tabula from 1508, features a marginal note mentioning the Inventio Fortunata:

"It is said in the book concerning the fortunate discovery that at the arctic pole there is a high magnetic rock, thirty-three German miles in circumference. A surging sea surrounds this rock, as if the water were discharged downward from a vase through an opening. Around it are islands, two of which are inhabited."

Gerardus Mercator's world map of 1569 reflects his reading of Cnoyen's Itinerarium. It also features a marginal note alluding to the Franciscan's "discovery", but not to the book itself, which he never saw:

"we have taken from the Itinerium of Jacobus Cnoyen of the Hague, who makes some citations from the Gesta of Arthur of Britain; however, the greater and most important part he learned from a certain priest at the court of the king of Norway in 1364. He was descended in the fifth generation from those whom Arthur had sent to inhabit these lands, and he related that in the year 1360 a certain Minorite, an Englishman from Oxford, a mathematician, went to those islands; and leaving them, advanced still farther by magic arts and mapped out all and measured them by an astrolabe in practically the subjoined figure, as we have learned from Jacobus. The four canals there pictured he said flow with such current to the inner whirlpool, that if vessels once enter they cannot be driven back by wind."

The Arctic map inset on Mercator's 1569 world map (seen here)--was the prototype for the influential and widely circulated Septentrionalium Terrarum of 1595, posthumously published by his son, and the maps in Ortelius's Theatrum Orbis Terrarum of 1570. Both show the same configuration of the arctic regions as the 1569 map.

In his letter to Dee, Mercator further quotes Cnoyen's description of the Northern regions:

"...In the midst of the four countries is a Whirlpool into which there empty these four Indrawing Seas which divide the North. And the water rushes round and descends into the earth just as if one were pouring it through a filter funnel. It is 4 degrees wide on every side of the Pole, that is to say eight degrees altogther. Except that right under the Pole there lies a bare rock in the midst of the Sea. Its circumference is almost 33 French miles, and it is all of magnetic stone. And is as high as the clouds, so the Priest said, who had received the astrolabe from this Minorite in exchange for a Testament. And the Minorite himself had heard that one can see all round it from the Sea, and that it is black and glistening. And nothing grows thereon, for there is not so much as a handful of soil on it."

The persistence of this idea of the geography of the far north persisted throughout the 16th and 17th century. This is probably due to the influence of Ruysch, Mercator, and Ortelius. Maps were only revised when the region was explored and mapmakers obtained knowledge of the true geography of the Arctic.

More interesting to modern researchers are the people the friar encountered- "pygmies" who may well be identical with the Skraelings referred to in old Norse texts about Greenland, predecessors of the modern Inuit.