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 broad levels, and on those of Plaistow and East Ham, where the land is comparatively cheap, the population has greatly increased despite the naturally undesirable character of the situation. The Gas-Light and Coke Company have created the village of Beckton, and other manufactories have attracted many workers.

The marshland disappears for a space at Purfleet and again at Grays, where the Thames in its windings almost touches the higher grounds of valley gravel. At Tilbury Fort there is again a wide spread of Alluvium, to which attention has been specially directed because at the base of the clays and peaty beds at a depth of a little over thirty feet there was found a human skeleton of prehistoric, but not, as was originally supposed, of palæolithic age. The beds above included peat and tidal clay, and the peat contained roots of birch and hazel, and remains of reeds, ferns and mosses. Above the uppermost layer of peat were evidences of Roman occupation.

At Thames Haven and Canvey Island there is a broad tract of marshland, consisting of fifty feet of clay, silt, sand and peat.

Marshlands border east Essex at Wakering, including Foulness and other islands, and northwards they extend along the Crouch valley below Rettenden, and from Burnham to Bradwell on the borders of the river Blackwater. On the opposite side Tollesbury Marsh is continued to the spit known as Shingle Head Point.

At the mouth of the Colne St. Osyth marsh extends towards Clacton-on-Sea, where the peaty portion of the Alluvium, clay with plant-remains, and stools and prostrate trunks of trees, exposed at low-tide, has given rise to a submerged forest. On the south side the marshes are bordered by a ridge of shingle and sand, 'which rises above the level of the highest tides, and still continues to increase in width although freely used for road-metal and ballast.'

South-west of Clacton there are thin fringes of Blown Sand, and there is a tiny patch at Stour Point between Walton-on-the-Naze and Harwich. Harwich itself appears to be built partly on marine sand.

These alluvial tracts comprise not only the old embanked areas below high-water mark, including islands and other tracts of excellent loamy soil adapted for grazing as well as arable ground, but they include also salt marshes or saltings which rise ten feet and more above Ordnance Datum. The spring tides cover these salt marshes, and by leaving thin films of sediment, tend gradually to raise their level, until in the end the sea may be excluded. As the saltings continually widen seaward, fresh strips have been from time to time enclosed. The trouble with all these marshlands has been the want of fresh water in dry seasons, but deep wells carried through the London Clay have provided a remedy.