The Roman altars, sculptured fragments, inscribed stones, coins, implements of war, articles of personal ornament, and utensils for domestic use, which have been found along the line of the wall, are extremely numerous. But far more striking memorials of Agricola and his great successors in Britain are the Roman roads. Easy means of communication were, of course, a necessity for the Romans, dwelling, as they did, as a military garrison among a people notorious for their propensity to break into wild rebellion at a moment's notice; and hence the country was traversed by a complete system of roads leading from station to station. The method of their construction varied, but they were invariably raised above the surface of the country, and ran in an almost straight line regardless of hill and valley. The more important roads were very elaborately constructed with a foundation of hard earth, a bed of large stones, sometimes two more layers of stones and mortar, and above all the causeway paved with stones. The four most important roads were Watling Street, the Foss, Icknield Street, and Ermine Street. Of these, Watling Street ran from London to Wroxeter (Uriconium), and thence was continued into Wales, while part of the same system connected London with Dover. The Foss ran from the sea-coast, at Seaton in Devonshire, to Lincoln, with a continuation known as the High Street to the Humber. The Icknield way started from near Bury and ran to Wantage, and thence to Cirencester and Gloucester. Ermine Street ran through the Fens from London to Lincoln. These by no means exhaust the Roman roads, traces of which are to be found in almost every neighbourhood of England, but they are the "four Roman roads" so frequently mentioned in the legislation of the Middle Ages. [Illustration: ROMAN MASONRY AT COLCHESTER.] [Illustration: BASEMENT OF STATION ON THE ROMAN WALL.]