towards the buoy of the Nore, where the body of their fleet lay, which lasted till about midnight.... Having seen this bold action, and their braving us so far up the river, I went home the next day, not without indignation at our negligence, and the Nation’s reproach.” In 1904 it was proposed in the House of Commons that there should be made at Gravesend a great barrage or dam, right across the River Thames, with a view to keeping a good head of water in the stream above Gravesend, much as the half-tide lock (about which we shall read in Book III.) does at Richmond. This, the proposers said, would do away with the cost of so much dredging, and would make the building of riverside quays a much simpler and more satisfactory matter, for by it the whole length of river between Gravesend and London would be to all intents converted into one gigantic dock-basin. It was proposed that the barrage should have in it four huge locks to cope with the large amount of shipping, also a road across the top and a railway tunnel underneath. But many weighty objections were urged, and numerous difficulties were pointed out, so that the scheme fell through; and so far the only semblance of a barrage known to Gravesend has been that which was thrown right across the lower River for defensive purposes during the Great War. CHAPTER FIVE _The Marshes_ The stretch between Gravesend and the beginnings of the Metropolis can scarcely be regarded as an interesting portion of the River. True, there are one or two places which stand out from the commonplace level, but for the most part there is nothing much to attract; and certainly from the point of view of the navigator of big ships there is much in this stretch to repel, for here are to be found the numerous shoals which tend to make the passage of the River so difficult. Indeed, the problem of the constant filling of the bed of the River has always been a difficult one with the authorities. The River brings down a tremendous quantity of material (it is estimated that 1,000 tons of carbonate of lime pass beneath Kingston Bridge each day), and the tides bring in immense amounts of sand and gravel. Now, what becomes of all this insoluble material? It passes on, carried by the stream or the tidal waters, till it reaches the parts of the River where the downflowing stream and the incoming sea-water are in conflict, and so neutralize each other that there is no great flow of water. Then, no longer impelled, the material sinks to the bottom and forms great banks of sand, etc., which would in time grow to such an extent that navigation would be impeded, were not dredgers constantly engaged in the work of clearing the passage. It was largely this obstacle to efficient navigation that led to the creation of the great deep-sea docks at Tilbury.