enty-five years, one month, and ten days. This survey, with the
supplementary surveys of the new provinces, as they were conquered and
added to the empire, formed the basis of the geography of Ptolemy. It
appears from Vegetius, that every governor of a province was furnished with
a description of it, in which were given the distance of places, the nature
of the roads, the face of the country, the direction of the rivers, &c.: he
adds, that all these were delineated on a map as well as described in
writing. Of this excellent plan for the itineraries and surveys of the
Roman empire, from which the ancient geographers obtained their fullest and
most accurate information, Julius Caesar was the author.

Julius Caesar certainly added much to geographical knowledge by his
conquests of Gaul and Britain: his information respecting the latter,
however, as might be expected, is very erroneous. Yet, that even its very
northern parts were known by name to the Romans soon after his death, is
apparent, from this circumstance, that Diodorus Siculus, who died towards
the middle of the reign of Augustus, mentions Orkas; which, he says, forms
the northern extremity of the island of Britain. This is the very first
mention of any place in Scotland by any writer.

One of the first objects of Augustus, after he had reduced Egypt, was to
explore the interior of Africa, either for the purpose of conquest, or to
obtain the precious commodities, especially frankincense and aromatics,
which he had learned were the produce of those countries. AElius Gallus was
selected by the emperor for this expedition, and he was accompanied by the
geographer Strabo; who, however, has not given such accurate information of
the route which was pursued as might have been expected. This is the more
to be lamented, as Pliny informs us that the places which were visited
during this expedition are not to be found in authors previous to his time.

Gallus was directed by the emperor to explore Ethiopia, the country of the
Troglodytae and Arabia. The expedition against Ethiopia, which Gallus
entrusted to Petronius, we shall afterwards examine, confining ourselves at
present to the proceedings and progress of Gallus himself. His own force
consisted of 10,000 men, to which were added 500, supplied by Herod, king
of the Jews; and 1000 Nabathians from Petra; besides a fleet of eighty
ships of war and 130 transports. Syllaeus, the minister of the king of the
Nabathians, undert