or stone, but after the 10th century they were printed from
wood-blocks. Among the more important productions of more
recent times, may be mentioned a map of the empire, said to be
based upon actual surveys by Yhang (721), who also manufactured
a celestial globe (an older globe by Ho-shing-tien, 4 metres in
circumference, was produced in 450), and an atlas of the empire on
a large scale by Thu-sie-pun (1311–1312) of which new enlarged
editions with many maps were published in the 16th century and
in 1799. None of these maps was graduated, which is all the
more surprising as the Chinese astronomers are credited with
having made use of the gnomon as early as 1000 B.C. for determining
latitudes.
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| Fig. 17.—Globe in Bibliothèque Nationale, Paris |
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| Fig. 18.—The Indian Ocean according to Mohit, as interpreted by Dr Tomaschek. |
In the case of Japan, the earliest reference to a map is of 646, in which year the emperor ordered surveys of certain provinces to be made.
Portolano Maps.—During the long period of stagnation in cartography, which we have already dealt with, there survived among the seamen of the Mediterranean charts of remarkable accuracy, illustrating the Portolani or sailing directories in use among them. Charts of this description are first mentioned in connexion with the Crusade of Louis XI. in 1270, but they originated long before that time, and in the eastern part of the Mediterranean they embody materials available even in the days before Ptolemy, while the correct delineation of the west seems to be of a later date, and may have been due to Catalan seamen. These charts are based upon estimated bearings and distances between the principal ports or capes, the intervening coast-line being filled in from more detailed surveys. The bearings were dependent upon the seaman’s observation of the heavens, for these charts were in use long before the compass had been introduced on board ship (as early as 1205, according to Guiot de Provins) although it became fully serviceable only after the needle had been attached to the compass card, an improvement probably introduced by Flavio Gioja of Amalfi in the beginning of the 14th century. The compass may of course have been used for improving these charts, but they originated without its aid, and it is therefore misleading to describe them as Compass or Loxodromic charts, and they are now known as Portolano charts.
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| Fig. 19.—The Eastern Mediterranean, by Petrus Vesconte (1311). |
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| Fig. 20.—The Mediterranean. |
| a, According to A. Dulceti, 1339, and b, On Mercator’s projection, according to modern maps. |
