This department of geographical history is only just beginning to be appreciated at its full value--as marking the vital transition from ancient to modern, from empirical to scientific--but this need not surprise us much. The portolani, as has been well said, never had for their object to provide a popular or fashionable amusement; they were not drawn to illustrate the works of classical authors or learned prelates; still less did they illustrate the legends and dreams of chivalry and historical romance; they were seldom drawn by learned men; and small enough in return was the acknowledgment which the learned but too often made them, when the great geographical compilers of the Renaissance and Reformation times incorporated the earlier coast-charts in grander and more ambitious works. Unquestionably, however, it is in maps of the portolano type that we must look for Prince Henry's primary geographical teachers, though the influence of books--and even of the older theoretical designs in cartography--must not be forgotten. Therefore, to understand his position--to realise what he had to draw from--we must briefly describe the chief designs which it was possible for him to consult for his scientific purposes, for his Ptolemaic ambition, διορθῶσαι τὸν ἀρχαῖον πίνακα [diorthôsai ton archaion pinaka]. (1) The "Carte Pisane" of the latest thirteenth or earliest fourteenth century is probably only a copy of an earlier work, though now itself our earliest example of the portolano type. The Mediterranean on this example (as well as the Black Sea, where it has survived injury) shows the new scientific or surveying method, but the Atlantic coasts of Spain and France, and still more the shore-lines of Britain, are of a different and inferior character. This alone points to an earlier date than, _e.g._, the works of Vesconte and Dulcert. In West Africa only a part of the Maroccan coast now remains. (2) The Map of Giovanni di Carignano,[246] of _c._ 1300?-1310, though much damaged, shows the Black Sea and Britain with contours differing somewhat from the ordinary portolan; and the same is noticeable in the Baltic. The West African coast does not extend to Cape Non. Another work by Carignano, of _c._ 1306, "specially referring to Central Asia," is said to exist, but its present position is unknown. [Footnote 246: Signed "Johannes presbyter, rector Sancti Marci de Porta Janue me fecit." A priest answering to this description flourished in Genoa, 1306-1344; this may have been a younger relative.] (3) A portolan of the early fourteenth(?) century, belonging to Professor Tammar Luxoro, of Genoa, in 1882, and usually called after him, is believed by Nordenskjöld to be a "slightly altered copy of the normal portolano in its original form." In N.W. Africa it only gives us the shore-line as far as Sallé, with a series of names, beginning at Arzilla.[247] [Footnote 247: No Atlantic islands exist on the Tammar Luxoro portolan.]