A good example of this was seen in the disastrous Mid-Level flood at Lynn in 1862[1] and the more recent outburst near Denver in the winter of 1914-15[2], of which accounts were published in contemporary newspapers. The varied accompanying phenomena can be well studied in the process of warping in Yorkshire or the colmata in Italy. [1] _Times_, _Cambridge Chronicle_, May 31, 1862. [2] _Times_, Jan. 16, 1915. This was a much commoner catastrophe in old times, before the banks were artificially raised, and, as the streams could never get back into their old raised channel, this accounts for the network of ancient river beds which intersect the Fens. The bottom of the Turbiferous alluvium is always, as far as my experience goes, sharply defined. This of course cannot be seen in a borehole or very small section. The surface of the older deposits seems to have been often washed clean either by the encroaching sea or by the upland flood waters. In saying that there is an absence of sand and gravel in the Fen Beds we must be careful not to force this description too far. For when the first encroaching water was washing away any pre-existing superficial deposits the first material left as the base of the Fen Beds must have depended upon the character of the underlying strata, the velocity of the water and other circumstances. This is well seen in the Whittlesea brickpit where an ancient gravel with marine shells rests on the Oxford Clay and over the gravel there creeps the base of the Turbiferous series. It here consists chiefly of white marl which thins out to the left of the section and above becomes full of vegetable matter until it passes up into peat, over which there is a flood-water loam. About a mile west-north-west of Little Downham near Ely, and within a couple of hundred yards of Hythe, the Fen Beds were seen in a deep cut carried close to the gravel hill which here stretches out north into the Fens. They consist at the base of material washed down from the spur of gravel and sand of the Areniferous series against which the Fen Beds here abut. This basement bed is succeeded by beds of silt and peat of no great thickness as they are near the margin of the swamp.