XIR370217 Water Balance, from \'Book of Knowledge of Ingenious Mechanical Devices\' by Al-Djazari, 1206 (vellum) by Islamic School, (13th century); Topkapi Palace Museum, Istanbul, Turkey; (add.info.: Al Jazari was a 12th century Muslim engineering genius and inventor; served the Urtuq court in Upper Mesopotamia in present-day Turkey; his name derives from the region of his birth, Al Jazira, between the Tigris and Euphrates; Balance a eau;); out of copyright.