'The sphere of nautical technology also includes chart making, and it was the Arabs who had done most to preserve the learning of the ancient world as it applied to cosmographic theory and its practical applications. While the Christian nations of Europe ignored what it considered the 'pagan' learning of the classical Mediterranean cultures, Muslim Scholars working in Alexandria and Baghdad were translating ancient Greek treatises on mathematics, astronomy, and geography as early as the ninth and tenth centuries' Source: Zvi Dor-Ner in 'Columbus and the Age of Discovery'