ii
The second system, as I have said, seems to have been connected with London, but here the later track of the Roman engineers and the continuous development of nearly twenty centuries has left us little to go on save conjecture. There are points in that conjecture, however, which are fairly certain. But there seems to have been, from the earliest time, communication between north and south on the lowest crossing of the Thames. Now, the lowest permanent crossing of the Thames, even before a bridge, was in the neighbourhood of London.
The crossing of a river is determined by the hardness of the land upon either bank, as we have seen, more than by any other factor. The lower Thames everywhere had extensive marshes either upon one side or the other, and usually upon both. At Grays, Tilbury, Erith, etc., the hard ground approached right up to one bank, but was always countered by extensive marshes on the other, or by marsh behind gravel, forming a sort of island of hard land which could not be used for continuous travel.
The first good crossing-place was at Lambeth, and it is generally assumed that the earliest of all the tracks took the stream here, for the alignment of the main approach from Kent through Canterbury, Rochester, and Shooters’ Hill does not point at the centre of London, but at Lambeth. This, it is presumed, was the track followed by what is now Park Lane, and so ultimately north-westward by the Edgware Road and its continuations to Chester, with a branch thrown off through the pass between the marshes of the Mersey and the Pennine range in the district of Manchester, and so on through Lancashire. But at some very early stage there was established a crossing below Lambeth in the neighbourhood of London Bridge, even before that bridge came into existence. It is true that there is here a belt of marsh on the right bank, but the considerable gravelly hill on the left, or north, bank there would give an opportunity not to be lost. It had three great advantages: it was a large area of dry land for settlement; it had defences all round it—marshy land to the north, the Fleet to the west, the Lea to the east; it had a considerable area for the drawing up of boats, and a steep shore for wharfage. Under these conditions, whenever men could first construct a causeway it would have been worth while to have been at that labour across the Southwark marshes in order to establish a permanent crossing by ferry, and later by a bridge, upon the site of London Bridge. At any rate, from that centre—London Bridge—at some very early period you get trackways radiating.
There is the main one, in the first place, through Canterbury to Dover and the Kentish ports. Next, there is the eastern one to Colchester, along which the chief Roman invasion marched to the capture of that town, which was the capital of the enemy.
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