GEOLOGY is given in his work, Man, the Primeval Savage (1894). Caddington lies nearly at the head of a dry valley which must have been excavated by a stream at one time flowing past Kinsbourne Green, Harpenden, and Sandridge, between the valleys of the Ver and Lea, and joining the Colne near Wilkins Green about midway between St. Albans and Hatfield, a distance, measured along the windings of the present valley, of 14 miles. This valley commenced in a swamp, outlying portions of which may have drained into the Lea on the east and the Ver on the west. Boulder clay then covered the hills ; only one patch of it has been left in position within a mile of Caddington, but its former presence elsewhere in this district is proved by the occurrence of a clay- stained Gryphaa and ice-scratched flints which must have been washed out of it, and by seams of the boulder clay itself which have been carried down to the horizon of the swamp. Close to the village ' an ancient chalk valley, filled in with water-laid brick-earth . . . serpen- tine on plan, as if made by a brook, has been followed in its curved course, and dug out by the brickmakers for the clay.' This appears to have led into the present dry valley of Ailey Green which joins the valley of the Ver at Friars Wash. The brickfields at Caddington are in loam or brick-earth overlying the Chalk, and it is in these that Mr. Worthington Smith has discovered a Palaeolithic floor or old land-surface on which primeval man lived near a shallow lake or swamp on the margin of which he established a manufactory of tools and weapons of flint. The heaps of flints have been found which were gathered together for the purpose, the finished and unfinished implements, and the flakes which have been struck off them, and Mr. Smith has pieced together the implements and flakes and built up the original flint. Many of these are described and illustrated in his work, in which he says that his Caddington reattachments then numbered over five hundred. The Palaeolithic workshops at Caddington are some feet beneath the present surface of the ground. The brick-earth in which they lie is mixed in places with Reading and other Tertiary clays and pebbles which have been washed into it from an old land-surface, and it fre- quently shows evidence of strong current-action, while around are patches of re-deposited chalk-with-flints and long stretches of red clay-with-flints, chiefly on the higher ground. In one section one workshop was seen a few feet above another, the older one having been covered up by an accumulation of brick-earth, on the surface of which the industry was again carried on. ' The descent of the red-brown stony clay,' Mr. Smith says, ' finally drove the Palaeolithic people away from the position.' And from the way in which the implements were left, finished and un- finished, and the presence of heaps of unworked flints, he is of opinion that the workmen were driven away in a hurry. The implements found in and about these Palaeolithic workshops, which are of lustrous flint, are not the oldest known to occur in this neighbourhood ; for others, ochreous in colour and more primitive in 29
