It was under AElius Gallus, the third prefect, that Egypt was visited by Strabo, the most careful and judicious of all the ancient travellers.  He had come to study mathematics, astronomy, and geography in the museum, under the successors of Euclid, Eratosthenes, and Hipparchus.  He accompanied the prefect in a march to Syene (Aswan), the border town, and he has left us a valuable account of the state of the country at that time.  Alexandria was the chief object that engaged his attention.  Its two harbours held more ships than were to be seen in any other port in the world, and its export trade was thought greater than that of all Italy.  The docks on each side of the causeway, and the ship canal, from the harbour of Eunostus to the Mareotic Lake, were full of bustle and activity.  The palace or citadel on the promontory of Lochias on one side of the great harbour was as striking an object as the lighthouse on the other.  The temples and palaces covered a space of ground equal to more than one-fourth part of the city, and the suburbs reached even beyond the Mareotic Lake.  Among the chief buildings were the Soma, which held the bodies of Alexander and of the Ptolemies; the court of justice; the museum of philosophy, which had been rebuilt since the burning by Caesar’s soldiers; the exchange, crowded with merchants, the temple of Neptune, and Mark Antony’s fortress, called the Timonium, on a point of land which jutted into the harbour; the Caesarium, or new palace; and the great temple of Serapis, which was on the western side of the city, and was the largest and most ornamented of all these buildings.  Farther off was the beautiful gymnasium for wrestlers and boxers, with its porticoes of a stadium in length, where the citizens used to meet in public assembly.  From the top of the temple of Pan, which rose like a sugar-loaf in the middle of the city, and was mounted by a winding staircase, the whole of this remarkable capital might be seen spread out before the eye.  On the east of the city was the circus, for chariot races, and on the west lay the public gardens and pale green palm-groves, and the Necropolis ornamenting the roadside with tombs for miles along the seashore.  Other tombs were in the catacombs underground on the same side of the city.  The banks of the Mareotic Lake were fringed with vineyards, which bore the famed wine of the same name, and which formed a pleasant contrast with the burning whiteness of the desert beyond.  The canal from the lake to the Nile marked its course through the plain by the greater freshness of the green along its banks.  In the distance were the new buildings of Augustus’ city of Nicopolis.  The arts of Greece and the wealth of Egypt had united to adorn the capital of the Ptolemies.  Heliopolis, the ancient seat of Egyptian learning, had never been wholly repaired since its siege by Cambyses, and was then almost a deserted city.  Its schools were empty, its teachers silent; but the houses in which Plato and his friend Eudoxus were said to have dwelt