Five Alexandrians

Socrates Scholasticus, writing within a generation, records that a Christian mob led by a man named Peter the Reader pulled Hypatia from her carriage, dragged her to the Caesareum church, and killed her with *ostrakois* — a Greek word that means either roof tiles or oyster shells. She was the most famous philosopher in the eastern Mediterranean and the head of the Alexandrian Neoplatonic school.

False. Caesar set fire to a shipyard in the Alexandria harbor during his 48 BC war against Ptolemy XIII. The fire spread along the docks and damaged some dockside warehouses (which may have contained scrolls). The main Library, several blocks inland in the royal quarter, was not affected — it is described as still functioning by Strabo, who visited the city 23 years later. The Library actually declined gradually over six centuries.

Eratosthenes measured the angle of the noon sun at Alexandria on the summer solstice (about 7°12') and compared it with the well at Syene (where the sun was directly overhead). He calculated the Earth's circumference at 250,000 stadia. Using the Egyptian stadion of 157.5 m — which most scholars now believe is what he used — that's about 39,375 km, against the actual 40,008 km. Under 2% off.

Theophilus, Patriarch of Alexandria from 385 to 412, used the Theodosian decree of February 391 (which banned pagan worship empire-wide) as cover to send a Christian mob against the Serapeum temple. The library, the cult statue of Serapis, and the temple itself were destroyed in the campaign. Cyril was Theophilus's nephew and successor, later responsible for Hypatia's murder.

Heiberg, working at the library of the Metochion of the Holy Sepulchre in Istanbul, identified the faint mathematical underwriting beneath a 13th-century Greek prayer book as Archimedes — including the only surviving copy of the *Method of Mechanical Theorems*. The manuscript later disappeared, resurfaced at Christie's in 1998, and was recovered by multispectral imaging at the Walters Art Museum.