You see, in the first place, that everything up to the very gates of London must have been, at the beginning of our history, as desolate as any province in Europe. The rare places at which high and firm land comes down to the modern stream are, as it were, isolated, and live a life upon the defensive. Nowhere (as we shall see when we come to examine London as a crossing place) does some good habitable site stretch down to either opposing bank. There is no natural gateway upon the Lower Thames; no twin villages defending a gap; nor the projection from the north as from the south of tongues of high land or even good arable land, the proximity of which, one to the other upon either shore, would give humanity to the river. All the miles of it are desolate marshes, either to the one side or to the other, most commonly upon both, and the few spots where an exceptional formation has given firm building ground and fertile fields as well close to the river have something about them exceptional and, as it were, beleaguered. It is a gross and an unhistorical exaggeration to say (as many of our academic people are saying) that all that valley was a flooded lagoon until historic times. It was not that. But it was a long succession of very wide, watery marshes, with knolls of slightly higher land standing up therein. Consider, for instance, the view to the northward, from the height just above and east of Dartford. There you have two good miles of what was marsh and still is largely marsh to the main stream, and beyond, upon the farther shore, another three or four miles of the same flats, with odd, exceptional rises at Rainham, at Aveney, or upon the edge of the flat of Upminster. It is the same from the Abbey Wood, east of Woolwich. Plumstead Marshes and Barking Level made one morass, four miles wide at least, or nearer five, drowned twice a day into a great level sheet of water, until some civilisation came to dyke up the tidal stream and confine it to the central bed, which it had scoured in its windings through such a desolation. Now of all that primitive effect of waste, abandoned places very much remains in such a journey as I have suggested. It is true that a wall of earth everywhere controls the flood to-day, and that the traveller in his boat does not see, as he would have seen two thousand years ago, the glint of water to the north and south at high tide over tufted grass and drowned banks of mud for miles upon either side of his going. But he still sees in so many places as to make them the chief note of the lower reaches, at least, great Flats without a soul upon them, unbroken by tree or house or hedge, and plainly saved by artifice alone from flooding. This run up the Lower Thames is, save for the exceptional approach of high land in one place or another (as at Gravesend or Erith) like a sail through the Fenland, and this character of desertion, silence, and morass, the oldest foundation of all, is still quite plainly the background of what