Latins at Byzantium alike read Heravy, like a Christian doctor. Another
example of the same catholic spirit is "Yacout the Roman,"[16] whose
_Dictionary_, finished in the earlier half of the thirteenth century,
was a summary of geographical advance since Edrisi, like the similar
work of Ibn Said, of the same period.

[Footnote 16: Yacout "the ruby," originally a Greek slave, who made a
brave but fruitless attempt to change his name into Yacoub or Jacob,
became one of the greatest of Arab encyclopædists, was checked by the
hordes of Genghiz-Khan in his exploration of Central Asia, and died
1229.]

But as a matter of fact, the balance both of knowledge and power was now
shifting from Islam to Christendom. The most daring and successful
travellers after the rise of the Mongols were the Venetian Marco Polo
and the Friar Preachers who revived Chinese Christianity (1270-1350);
Madeira and the Canaries (off Moslem Africa) were finally rediscovered
not by Arabic enterprise, but by the Italian Malocello in 1270, by the
English Macham in the reign of our Edward III., and by Portuguese ships
under Genoese captains in 1341; in 1291 the Vivaldi ventured beyond Cape
Bojador, where no Moor had ever been, except by force of storm, as in
the doubtful story of Ibn Fatimah, who "first saw the White Headland,"
Cape Blanco, between Cape Bojador and Cape Verde.

In the fourteenth century the map of Edrisi was superseded by the new
Italian plans and coast-charts, or Portolani. As the Moslem world fell
into political disorder, its science declined. "Judicial astrology"
seemed gaining a stronger and stronger hold over Islam, and the
irruption of the Turks gradually resulted in the ruin of all the higher
Moslem culture. Superstition and barbarism shared the honour and the