This and other great roads grew gradually to perfection throughout the country for four hundred years. Towns and military stations dotted them at intervals, and in between the abodes of men the way was lined, after the custom of the Roman people, with tombs and cemeteries. This explains the many "finds" of sepulchral urns and various relics beside the road. [Sidenote: THE OLD ROADS] When the Saxons came, they could not pronounce the name by which the half-Roman people called this road, and so "Gwyddelin" became "watling" on their tongues, while "strata" was corrupted to "street." No new roads were made now, and, indeed, not until the Turnpike Acts of George the Third's time and the era of MacAdam was the art of road-making practised again in England. For ages the "roads" of this country were a byword and a reproach to us. By the middle of the twelfth century the Roman roads that had been made and kept in repair for hundreds of years fell into ruin, and the detritus and miscellaneous accumulations of twenty-five generations now cover the greater portion of them. At a depth varying from five to fourteen, and even eighteen, feet, excavators have come upon the hard surface of the original Roman road, and mosaic pavements of villas found at that extreme depth attest how the surface of a country may be altered only by the gradual deposit of vegetable matter. The thickest deposits are found in low-lying situations, where the flow of streams or rain-water has brought liquid earth to settle upon the deserted sites of an ancient civilisation. This has occurred notably at such places as Dartford, Rochester, and Canterbury, all situated in deep valleys, where springs and storms have united to bring mud, sand, and gravel down from the hillsides, and thus to equalise in some measure the ancient irregularities of the scenery. While the hollows have thus been rendered less profound, the hill-tops and table-lands have remained very much as they were, and it is in these elevated situations that the line of Watling Street can most readily be traced, or _could_ have been had not the stone pavings that composed the road been long ages ago abstracted.