This vague sketch of the old trackways is all that we can lay down so far as their main lines are concerned, and it is very imperfect, but we must bear it in mind in order to understand the Roman system, which was largely based upon those trackways and which superseded them. There was one kind of soil, and one only, which could compete with the chalk as good going for primitive travel, and that was sand. Had we sand in continuous lines in Britain it would have given a dry passage for the trackways, and here and there advantage is taken of it by such trackways. But sand, in point of fact, is not to be found in these continuous lines. It comes in patches, and hence we cannot talk of any one of the great trackways as dependent upon a sandy soil. The chief exception that I can call to mind in this respect is the run of the old Pilgrims’ Way--a prehistoric track from the neighbourhood of Farnham to the crossing of the Mole, near Dorking. Though chalk lay on the main direction, it seems to have preferred the southern dry sand to the chalk immediately north of it, and it keeps to the sand until the cessation of that formation a short distance west of the Mole. There is here a curious piece of political geology which has been, I think, of great effect upon the history of England. Had the ridges of sand through the weald of Sussex been _continuous_, the weald would have been developed early. Its iron industry would have furnished a basis for export, and it would have become one of the centres of population. There are ridges of sand which you can trace all the way through the weald from close by the Hampshire chalk in the neighbourhood of Midhurst right away to the valley of the Rother. But they are not continuous, and the interruptions are formed of deep clay, impossible to pass in winter. The result of that lack of continuity has been that no such track ever developed through the weald of Sussex. Sussex, therefore, owing to the stiff clay of its weald, remained cut off from the rest of England, and that throughout all the Dark Ages. It falls out of the national history. Indeed, the linking up of Sussex with the north was only effected by the Romans at the cost of great labour through the artificial causeway of the Stane Street between Chichester and London; and after the breakdown of western civilization in the fifth century there was no regular approach to the southern coast from the Thames valley in a direct line. The traffic either went westward down towards Southampton, Hampshire, Dorset, and Devon or eastward to the Straits of Dover. The Norman Conquest and the rule of the Angevins restored Sussex to something of its rightful place in English communications because the coast of that county lay immediately opposite the centre of the foreign region which then governed England, but the interlude was not lengthy. In the later Middle Ages and on to quite modern times (to the middle of the eighteenth century) the