The second symposium was the First International Workshop on the Origin and Evolution of Portolan Charts
were the fruits of the first systematic marine surveys.
Blake relates the development of the sea chart from the days when manuscripts were drawn on sheep skins, such as the portolan charts
that survived from the thirteenth century, through the maritime ascendancy of the Spanish and Portuguese, then the Dutch, French, and British through the eighteenth century, when the discovery and charting of the coasts and the oceans of the globe had become a strategic naval and commercial requirement, to the modern Admiralty charts of today.
In the last part, 'The Mediterranean Road,' Paul Kunitzsch presents the tools of premodern Arabic-Islamic astronomers such as three-dimensional celestial globes and the astrolabe, and finally Sonja Brentjes states that elements in fourteenth-century Catalan portolan charts
are similar to the late Ilkhanid school.
And when discussing attempts to adapt the technology of portolan charts
to the open oceans, he confuses the function of the oblique meridians found in extreme northern latitudes on some charts as providing a correction of scale, when in fact these oblique meridians were a (misguided) effort to correct for direction in these latitudes.
His most brilliant ideas--which should have been more fully developed--unify the symbolism and structural elements of portolan charts
within a general discussion of central and peripheral space.
Chapter 2 'Landmarks of Mapping' provides historic context with the usual references to Mappae Mundi, portolan charts
and so on, as well as maps from the ancient worlds.
He certainly had access to a library, for the map has been compiled from a wide variety of written itineraries and from portolan charts
used by seafarers.
The genesis of portolan charts in Europe apparently did not follow this rule.
Beyond their obvious appeal as conveyors of cartographic content, portolan charts provide a glimpse into the practical world of sea travel in the fifteenth and sixteenth centuries.
Such "transitional" maps blended components of Portolan charts
, Ptolemy's Geographia, and biblical themes.
MEDITERRANEAN PORTOLAN CHARTS
OF THE 14TH TO 17TH CENTURY