carried to the more distant fields, were, of course, each year more or
less blocked up by the same mud which made the fields fruitful; and the
clearing of these canals was one of the greatest boons that the monarch
could bestow upon the tillers of the soil. This had often been neglected
by the less powerful and less prudent kings of Egypt, in whose reigns
the husbandman believed that Heaven in its displeasure withheld part
of the wished-for overflow; but Petronius employed the leisure of his
soldiers on this wise and benevolent work. In order better to understand
the rise of the Nile, to fix the amount of the land-tax, and more fairly
to regulate the overflow through the canals, the Nilometer on the Island
of Elephantine was at this time made.

[Illustration: 011.jpg THE NILOMETER AT ELEPHANTINE]

It was under Ælius 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 Syênê (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