Unsolved Mysteries of the Portolans
Research, the Path to Solving the Mysteries
Despite much good work in the past century, fundamental research about portolan charts remains to be done.
1. Some of it could be fairly simple, such as gathering more information about them so that comparisons of their physical characteristics can be made.
2. The handwriting on them could be studied with the same care that is given to other manuscripts, since this may contain valuable clues about their creation.
3. Some comparisons of outlines of coasts have been made where two or more portolan charts were produced in the same location; with today’s sophisticated digital cameras and photocopiers, better reproductions for researchers can be made.
4. More needs to be known about the inks and paints used on the portolan charts.
5. The question of the relationship between the use of the compass in the Mediterranean (beginning in the thirteenth century) and the making of portolan charts should be pursued, particularly about the effect of magnetic variation (see works of Kelley and Lanman).
6. Questions concerning projection in the portolan charts are important, and more research is needed.
7. Stylistic elements, such as flags, should be studied.
8. Finally, it would be wonderful to know more about the forty-six chart-makers known from the fourteenth and fifteenth centuries, and indeed, about the trade that employed them (Campbell 1987).
The tendency to focus only on the part of the portolan chart which is of the greatest interest — the western islands, for example — does not help in learning more about the larger picture with regard to these fascinating maps.