The Vinland Map, acquired by Yale University during the mid-1960s, was said to demonstrate that the Norse had landed in North America well before Columbus. Many scholars pored over the crude cartography, which seemed to depict a pre-Columbian depiction of a coast that was soon to become famous for its rich cod fisheries. From the beginning, serious doubts were raised over the authenticity of the document, with a growing consensus that it was a 20th century forgery. For example, a Chicago study in 1973 established that the ink contained anatase, a form of titanium dioxide first used commercially during the 1920s.
A comprehensive new study has brought together Yale University Library conservators with a team of other scientists on campus. The experts compared the map with other 15th century documents with which it was bound. Worm holes in a medieval encyclopaedia matched holes in the map. Most likely, it was drawn on one of the encyclopaedia’s end sheets. The team also focused on the map’s ink, using X-ray fluorescence spectroscopy (XRF). This produced an elemental map of the document, so they looked at the entire map. The scan showed titanium throughout the map’s ink. The American coastline revealed high levels of titanium and smaller amounts of barium, found in titanium-white pigments produced commercially during the 1920s.
Astonishing detective work, but very important, for the Vinland Map has become a historical object in its own right. It will remain in the Beinecke Library at Yale together with the other documents that were used to show definitively that it is a 20th century fake.