"Medieval Islam was technologically advanced and open to innovation. It achieved far higher literacy rates than in contemporary Europe; it assimilated the legacy of classical Greek civilization to such a degree that many classical books are now known to us only through Arabic copies. It invented s, , sails and made major advances in metallurgy, mechanical and chemical engineering and methods. In the middle-ages, the flow of technology was overwhelmingly from Islam to Europe rather from Europe to Islam. Only after the 1500s did the net direction of flow begin to reverse."