against the position we have laid down and endeavoured to prove, that in
the time of the Ptolemies the commerce of Egypt was confined within the
limits of the Red Sea, partly from the want of skill and enterprize, and
from the dangers that were supposed to exist beyond the straits, but
principally because the commodities of India could be procured in the ports
of Sabæa.

Many instances have already been given of the patronage which the Ptolemies
bestowed on commerce, of the facilities and advantages they afforded, and
of the benefits which the science of geography derived from the library and
observatory of Alexandria: every instrument which could facilitate the
study of astronomy was purchased by the Ptolemies and placed in that
observatory, for they were fully aware of the dependency of a full and
accurate knowledge of geography, as a science, on a full and accurate
knowledge of astronomy. With respect to commerce, the advancement of which,
may fairly be supposed to have had some weight in their patronage of these
sciences, they encouraged it as much as possible to centre in Alexandria,
and with citizens of Egypt, by making it a standing law of the country,
that no goods should pass through the capital, either to India or Europe,
without the intervention of an Alexandrian factor, and that even when
foreign merchants resided there, they should employ the same agency. The
roads and canals they formed, and the care they took to keep the Red Sea
free from pirates, are further proofs of their regard for commerce.

And justly was it held by the Ptolemies in high estimation, for from it
they derived their immense wealth. We are informed by Strabo, that the
revenue of Alexandria, in the worst of times, was 12,500 talents,
equivalent to nearly two millions and a half sterling; and if this was the
revenue under the last and most indolent of the Ptolemies, what must it
have been under Ptolemy Philadelphus, or Ptolemy Euergetes? But the account