Diagram of the Correct Shape of an Ostrich

"After [Hulagu] captured the Assassin eyrie of Maimundiz, almost the only inmate he spared was the celebrated astronomer Nasar ad-din Tusi, who had persuaded the wavering Grand Master that the planets favored surrender. To Tusi Hulagu entrusted the creation of an observatory on the plateau above Maragheh, which was soon bristling with the latest refinements of science and magic. By a pinpoint of sunlight through its dome a giant quadrant assessed the meridian altitudes of the sun, and an army of other instruments--armillary spheres, astrolabes, a dioptra for measuring the diameter of sun and moon--were built out under the stars. Even Chinese astronomers were recruited; and a library of four hundred thousand volumes, many salvaged from [the sack of] Baghdad, confirmed the observatory as the greatest of its time.

Within thirty years, using instruments more precise than those of Copernicus two centuries later, its scholars produced astronomic tables of an accuracy to supersede the calendar derived from Ptolemy. But Hulagu--addicted to alchemy and astrology--could not wait for Saturn to complete its thirty-year revolution. For him the heavens were the mind of God; they moved affairs below. And he would soon be dead. He demanded results within twelve years.

...Then the Ilkhanid dynasty fractured, and by 1340 the observatory lay in ruins. Some sixty years later, Ulug Beg, the astronomer-grandson of Tamerlane, wandered its ruins as a child, enchanted." --Shadow of the Silk Road