Two other libraries also helped to make up the glory of Alexandria; one in the Sebasteum, or Temple of Augustus, and one in connection with the Museum. The latter, however, was a much later foundation. The museum or university itself, had been instituted by Ptolemy Soter, and though it was quite distinct from the library which is associated with his name, there was doubtless some relationship between the two. Her museum and libraries, and the encouragement she offered to learning, combined to set Alexandria at the head of the literary world, and to make her "the first great seat of literary Hellenism" (Jebb). She was also the centre of the book industry, that is, of the reproduction of books, as distinguished from their first production. This was owing in a large measure to the number of professional copyists attracted by the facilities afforded to them, and to the fact that the papyrus trade had its headquarters here. Another famous library of this period was that of the Kings of Pergamus, founded by Attalus I., who reigned from 241 to 197 B.C. Between Pergamus and Alexandria there was vigorous competition. In the end, however, Alexandria had the satisfaction of seeing her rival completely humbled, for Antony presented the books of Pergamus, stated to have been about two hundred thousand in number, to Cleopatra, who added them to Alexandria's treasures. At least, so says Plutarch, but Plutarch's authority for the statement was Calvisius, whose veracity was not above suspicion. How the enormous accumulation of manuscripts gathered by Alexandria came to perish so utterly is not clear. The Romans accidentally fired the Bruchium when they reduced the city, but according to several accounts there were still a goodly number of books remaining at the time of the Saracen invasion in 638 A.D. The story of the Caliph Omar's reply to a plea for the preservation of the books is well known. "If they contain anything contrary to the word of God," he is reported to have said, "they are evil; if not, they are superfluous," and forthwith he had them distributed among the four thousand baths of the city, which they provided with fuel for six months. But several authorities doubt this story, and assert that long before Omar's time the Alexandrian libraries had ceased to exist.