The River of London

by Hilaire Belloc

We have, then, on the north, only Purfleet and Grays; and both must be rejected. On the south, however, there is a series of isolated natural wharves which approach the main tidal stream, and not only stand fairly steep-on to its rise and fall, but are further of a soil upon their surface which permitted travel and an easy approach to the river in early times. These are, counting from the sea-reaches upward: Gravesend, where the chalk comes right down to the Thames; Greenhithe, where a tongue of the chalk juts out and touches the water; Erith, the point where the gravels, which some mighty stream laid down when the rivers of Northern Europe were discharging ten, twenty, or a hundred times the flood they have to-day, first approach the existing stream. At Woolwich sand and gravel closely approach the river and line it for so considerable a distance as to afford the platform for a fairly large town. Next up-river the same formation of gravels gives at Greenwich a hard along the stream, and immediately above another spit of the same actually touches the river at the point where used to stand the isolated village of Deptford.

GREENWICH

Now any one of these natural hards along the south bank of the Thames between London and the sea would have afforded an excellent platform for the crossing of the river. It is true that the Thames is somewhat wider in its lower reaches than at the pool, but the difference was not so considerable as to balk those who first instituted the ferry and later the bridge of London. If one could cross the half-mile of water which lay before one at extreme high tides under the earliest conditions at Southwark, or bridge (as was done so long ago) the four hundred yards of the mainstream, there would have been no difficulty in dealing with the quarter of a mile at Deptford or at Greenhithe, nor even with the rather broader stream opposite Woolwich.

Save perhaps by a bridge of boats, a permanent crossing could not have been attempted at Erith or at Greenhithe, though the narrowing of the stream at Gravesend might well have allowed a more stable structure to be established. At any rate, a crossing even so broad as that opposite Erith has nowhere in Europe interfered with the passage of commerce, or of arms where both sides of a great stream lent themselves to such a passage. But it is here that each one of the points I have mentioned is at fault. Opposite Gravesend as opposite Greenhithe, opposite Erith as opposite Woolwich, Greenwich, and Deptford, there lies upon the northern bank a belt of marsh which forbids traffic. Tilbury Fort, opposite Gravesend, stands upon a tiny circle of harder land, but all around it are the Chadwell and the Tilbury marshes. Greenhithe has right against it the projecting expanse of West Thurrock Marsh, Erith the whole breadth of Wellington and Rainham marshes; and, as one approaches London, and the river narrows, matters seem only to get worse. Woolwich faces the expanse of originally flooded soil between the Lea and the Roding, with the most of which even the economic forces making for the expansion of London have been able to do nothing, and of which so unpleasant a relic of its original condition is left in Plaistow Marshes to-day; while opposite Greenwich and Deptford lay that perfectly impossible morass, which, though turned into water meadows by a river wall many centuries ago, is still perhaps the worst building ground within the London area. We call it the Isle of Dogs.

The reader must not imagine this lack of any two opposing hards upon London River below the City to be due to some coincidence. It has a fairly obvious geographical cause. Those points where the gravels and the chalk were touched by the scouring of the stream were naturally the outer cusp of its curves. The river having first determined a bend to the south or to the north, would eat away more and more on the outer edge of those bends (which the stream always follows both in flood and in ebb), and scour away the bank until it struck harder soils and was there checked. Deptford and Greenwich lie on the outer edge of the first great southern bend; Woolwich on that of the second; Erith on that of the third; Greenhithe the fourth; Gravesend the fifth; while both Grays and Purfleet represent similar checks to the bends towards the north.

Now it is evident that the same process which makes a river extend its curves outward more and more by the scouring the stream along the exterior edge leaves on the inside of the curve an increasing tongue or wedge of alluvial deposit. What we have, therefore, on the Lower Thames, the continual opposition of marsh to the rare hards, is only what we should expect from the geological history of the river, and the crossing place which was at last found is much more of a coincidence and accident than the absence of a crossing place below.

That crossing place was, of course, finally discovered opposite the steep gravel bank upon which the oldest part of the City of London is built.

The land has been so often turned and returned in at least twenty centuries of building that it is not easy to-day to reconstruct the original conditions of that crossing; and, unless we look at all the evidence, slight as it is, it is easy to fall into errors upon it. Thus several writers upon this subject have often spoken as though the gravel-topped knoll upon which the original London stood was the sole factor in establishing the crossing, and I have myself fallen into the error of believing that the approach from the south could only be made over a long artificial causeway.