Contrast between Byzantium and Calchedon
What then makes Byzantium a most excellent site, and
Calchedon the reverse, is just this: and although at first sight
both positions seem equally convenient, the practical fact is
that it is difficult to sail up to the latter, even if you wish to do
so; while the current carries you to the former, whether you
will or no, as I have just now shown. note And a proof of my
assertion is this: those who want to cross from Calchedon to
Byzantium cannot sail straight across the channel, but coast up
to the Cow and Chrysopolis,—which the Athenians formerly
seized, by the advice of Alcibiades, when
they for the first time levied customs on
ships sailing into the Pontus, note—and then drift down
the current, which carries them as a matter of course to
Byzantium. And the same is the case with a voyage on
either side of Byzantium. For if a man is running before a
south wind from the Hellespont, or to the Hellespont from the
Pontus before the Etesian winds, if he keeps to the European
shore, he has a direct and easy course to the narrow part of the
Hellespont between Abydos and Sestos, and thence also back
again to Byzantium: but if he goes from Calchedon along the
Asiatic coast, the case is exactly the reverse, from the fact that
the coast is broken up by deep bays, and that the territory of
Cyzicus projects to a considerable distance. Nor can a man
coming from the Hellespont to Calchedon obviate this by
keeping to the European coast as far as Byzantium, and then
striking across to Calchedon; for the current and other circumstances which I have mentioned make it difficult. Similarly,
for one sailing out from Calchedon it is absolutely impossible to make straight for Thrace,
owing to the intervening current, and to the fact that both winds are unfavourable
to both voyages; for as the south wind blows into the
Pontus, and the north wind from it, the one or the other of
these must be encountered in both these voyages. These,
then, are the advantages enjoyed by Byzantium in regard to
the sea: I must now describe its disadvantages on shore.