ased their fleet by the
capture of a number of fishing vessels, near the mouths of the Borysthenes,
the Niester, and the Danube, they plundered the cities of Bithynia. And in
a third expedition, in which their force consisted of five hundred sail of
ships, each of which might contain from twenty-five to thirty men, they
passed the Bosphorus and the Hellespont, and ravaged Greece, and threatened
Italy itself.

The extent to which some branches of trade were carried by the Romans about
this time, may be deduced from what is related of Firmus, whose ruin was
occasioned by endeavouring to exchange the security of a prosperous
merchant for the imminent dangers of a Roman emperor. The commerce of
Firmus seems principally to have been directed to the east; and for
carrying on this commerce, he settled himself at Alexandria in Egypt.
Boasting that he could maintain an army with the produce of paper and glue,
both of which articles he manufactured very extensively, he persuaded the
people of Egypt that he was able to deliver them from the Roman yoke, and
actually had influence sufficient to prevent the usual supplies of corn
from being shipped from Alexandria to Rome. His destruction was the
consequence. As an instance of his wealth and luxury, Vopiscus relates that
he had squares of glass fixed with bitumen in his house. The Roman commerce
suffered considerably during the reign of Dioclesian by the revolt of
Britain, under Carausius, who, by his skill and superiority, especially in
naval affairs, which enabled him to defeat a powerful Roman fleet fitted
out against him, obtained and secured his independence. Carausius was
murdered by Alectus: against the latter the emperor Constantine sailed with
a powerful fleet, and having effected a landing in Britain, Alectus was
defeated and slain. This fleet requires to be particularly noticed from two
considerations. In the first place, it sailed with a side wind, and when
the weather was rather rough,--circumstances so unusual, if not
unprecedented, that they were deemed worthy of an express and peculiar
panegyric: and, secondly, this fleet was not equipped and ready for sea
till after four years' preparation, whereas, in the first Punic war,
"within sixty days after the first stroke of the axe had been given in the
forest, a fleet of 160 galleys proudly rode at anchor in the sea."

Soon after this event, we are furnished with materials, from which we may
judge of the comparative opulen