2. All these cities were connected with one another and with Rome itself by means of the public highways: these issuing from the forum, traversed Italy, pervaded the provinces, and were terminated only by the frontiers of the empire. The great chain of communication formed by means of them from the extreme north-west limit of the empire, through Rome to the south-east limit, was in length nearly 4000 miles. These roads were formed in the most substantial manner, and with astonishing labour and expence; they were raised so as to command a prospect of the adjacent country; on each side was a row of large stones for foot passengers. The miles were reckoned from the gates of the city and marked on stones: at shorter distances there were stones for travellers to rest on, or to assist those who wished to mount their horses: there were cross roads from the principal roads. The care and management of all the roads were entrusted only to men of the highest rank. Augustus himself took charge of those near Rome, and appointed two men of prætorian rank to pave the roads: at the distance of five or six miles houses were built, each of which was constantly provided with forty horses; but these could only be used in the public service, except by particular and express authority. By means of the relays thus furnished, the Romans could travel along their excellent roads 100 miles a day: they had no public posts. Augustus first introduced public couriers among the Romans; but they were employed only to forward the public despatches, or to convey public intelligence of great and urgent importance. Such was the facililty of communication by land from all parts of the empire to Rome, and from each part to all the other parts: nor was the communication of the empire less free and open by sea than it was by land. "The provinces surrounded and enclosed the Mediterranean; and Italy, in the shape of an immense promontory, advanced into the midst of that great lake." From Ostia, situated at the mouth of the Tiber, only sixteen miles from the capital, a favourable wind frequently carried vessels in seven days to the straits of Gibraltar, and in nine or ten to Alexandria, in Egypt. 3. In enumerating the principal articles imported into Rome, for the use of its immense and luxurious population, we shall, necessarily, recapitulate, in some degree, what has already been stated in giving an account of the commerce of the different countries which were conquered by the Romans. But this objection, we conceive, will be abundantly counterbalanced by the connected and complete view which we shall thus be enabled to give of the commerce of the Roman empire.