At present there are two small islands, one towards either shore; that of Europe is distinguished by the column of Pompey.] [Footnote 7: The ancients computed one hundred and twenty stadia, or fifteen Roman miles.

They measured only from the new castles, but they carried the straits as far as the town of Chalcedon.] [Footnote 8: Ducas.Hist.c.34.Leunclavius Hist.

Turcica Mussulmanica, l.xv.p.577.Under the Greek empire these castles were used as state prisons, under the tremendous name of Lethe, or towers of oblivion.] [Footnote 9: Darius engraved in Greek and Assyrian letters, on two marble columns, the names of his subject nations, and the amazing numbers of his land and sea forces.

The Byzantines afterwards transported these columns into the city, and used them for the altars of their tutelar deities.

Herodotus, l.iv.c.