280 ON THE REMAINS OF A SUPPOSED PILE-DWELLING AT WOODHAM WALTER, ESSEX. BY MILLER CHRISTY, F.L.S. THE large expanse of waste land known as Woodham Walter Common is intersected, near its southern extremity, by a small streamlet, which occupies a remarkably-narrow steep- sided valley—certainly one of the narrowest, deepest, and most picturesque valleys in Essex. This stream, after leaving the Common on its eastern side, runs past the village of Woodham Walter, and thence into the Chelmer near Ulting Hall. About two hundred yards below the point at which the stream leaves the Common, its valley is crossed, at a specially- narrow place, by a massive artificial dam of earth, about fifty yards long and twenty-five feet high. This clearly once held up a mill-pool five or six acres in extent, but is now cut through by the stream. The dam has evidently been broken for a long period ; for oaks and other trees at least several hundred years old grow on the dam itself and on ground which once formed the bottom of the pool. Similar dams are found commonly throughout Essex, wher- ever the valley of a stream permits of one being constructed with advantage. They held up the waters which, in Mediaeval times, supplied the power needed to drive corn-mills, fulling-mills, and the like. Their pools served also as fish-ponds in the days when means of transport were so bad that fresh sea-fish were almost unknown, except upon the coast, and fresh-water fish were of real importance as a form of food-supply. Sometimes a string of such pools exists, one above the other, along a valley, as at Leighs Priory, Woodham Walter Hall, and elsewhere in this county. About a hundred yards below the large dam above-mentioned is a much smaller dam, not more than about twenty yards long and ten feet high. This is also broken. It is situated just below the point at which a small tributary streamlet joins the main valley, and can never have held up a pool of more than an acre in extent. The bed of the pool is now overgrown with bushes, while an oak of fair size grows actually on the dam itself. One