And the same may be said of the still wider strait which separates England from France. No geologist could look either at the Needles and Ballard Foreland, or at Shakespeare's Cliff and Cape Grisnez, without a conviction that the chalk ridge was once continuous, and has been worn away, inch by inch, by the very same process as is now going on. Nor can the action of ice or river floods be evoked to accelerate the process, for evidently it has throughout been a case of marine erosion. The only question is whether this dates back even into the later phases of the glacial period, for the opposite cliffs show no sign of having been either depressed beneath the sea or elevated above it, but rather appear to have stood at their present level since the erosion began. In any case it can only have occupied a comparatively short and recent phase of the glacial period, for there is abundant evidence that the British islands have been connected with the Continent in comparatively recent times. Great, however, as is the antiquity shown by these comparatively modern instances, they sink into insignificance compared with that shown by a recent discovery, which I quote the more readily because it rests on the high authority of Professor Prestwich, who has been foremost among modern geologists in reducing the time required for the glacial period and for the existence of man. This is afforded by the upland gravels in Kent and Surrey, which are scattered over wide areas of the chalk downs and green-sand, at elevations far above existing valleys and watersheds, and which could only have been deposited before the present rivers began to run, and when the configuration of the country was altogether different. Quite recently Mr. Harrison, a shopkeeper at Ightham in Kent, who is an ardent field-geologist, discovered palæolithic implements, in considerable numbers and in various localities, up to an elevation of 750 feet above the sea level, in these gravels of the great southern drift. These discoveries, which have since been repeated by other observers, led Professor Prestwich to institute an exhaustive inquiry as to these upland drifts; and the startling conclusion he arrives at is, that the oldest of them, or great southern drift, in which the implements are found, could only have come from a mountain range 2000 to 3000 feet high, which formerly ran from east to west in the line of the anticlinal axis which runs down the centre of the present Weald of Kent, between the north and south chalk-downs, and which has been since worn down to the present low forest-ridge by sub-aërial denudation. The reasoning by which this inference is supported seems irresistible. The drift could not have been deposited by the present rivers or with the present configuration of the country, for it is found at levels 300 or 400 feet higher than the highest watersheds between the existing valleys. It consists not only of chalk flints,