The road so laid was meant for permanence. A width of ground was carefully prepared, trenches were dug at the sides, three different layers of road material were deposited, with sufficient upward curve to throw off the water, and then the whole was paved with closely-fitting many-cornered blocks of stone. In the chief instances there were sidewalks covered with some kind of gravel. The width was not great, but might be anything between ten and fifteen feet. Along such roads the Roman armies marched to their camps, along them the government despatches were carried by the imperial post, and along them were the most conveniently situated and commodious houses of accommodation. For their construction a special grant might be made by the Roman treasury--the cost being comparatively small, since the work, when not performed by the soldiers, was done by convicts and public slaves--and for their upkeep a rate was apparently levied by the local corporations. Besides the paved roads there was, needless to say, always a number of smaller roads, many of them mere strips of four feet or so in width; there were also short-cuts, by-paths, and ill-kept tracks of local and more or less fortuitous creation. [Illustration: FIG. 2.--THE APPIAN WAY BY THE SO-CALLED TOMB OF SENECA.] Beside the great highways stood milestones in the shape of short pillars, and generally there were in existence charts or itineraries, sometimes pictured, giving all necessary directions as to the turnings, distances, stopping-places, and inns, and even as to the sights worth seeing on the way. Wherever there were such objects of interest--in Egypt, Syria, Greece, or any other region of art, history, and legend--the traveller could always find a professional guide, whose information was probably about as reliable as that of the modern _cicerone_. In Rome itself there was displayed, in one of the public arcades, a plan of the empire, with notes explaining the dimensions and distances.