270 NATURAL SCIENCE. Oct., 



their staining in their present position. A few only have been found 

 beneath the surface. 



It is very desirable that excavations should be made at proper 

 places on the plateau to discover, if possible, the extent and thickness 

 of the implementiferous soil. 



The peculiar reddish-brown colour of these rude implements, 

 with ochreous stain and some adherent particles of limonite, was 

 probably obtained when they were lying in an old ferruginous gravel 

 in their original place ; and some of this gravel has accompanied them 

 to the plateau. Their colour and greater wear distinguish them from 

 the few palaeolithic and neolithic worked flints found on the plateau. 

 Some have a strong resemblance to the " valley forms," and were most 

 probably transitional in character and condition. Many are very much 

 water-worn — an indication of their long and distant travel. Some are 

 scratched,- by very close pressure, either with or without the inter- 

 vention of ice-action. 



The evidences borne by these peculiarly-shaped flints of their 

 having been fashioned by the hand of Man, have been carefully dealt 

 with by Professor Dr. Prestwich (see above), Messrs. B. Harrison (their 

 discoverer), De B. Crashaw, W. J. Lewis Abbott, A. Montgomerie 

 Bell, and others. Mr. J. Allen Brown has succinctly referred to them as 

 " Eolithic : roughly-hewn pebbles and nodules, and naturally broken 

 stones, showing work, with thick ochreous patina ; found on the plateaux 

 of the Chalk and other districts, in beds unconnected with the present 

 valley-drainage " ; and " under conditions which clearly indicate that 

 they are older than the usual valley-drift implements." (jfoiirn. 

 Anthvop. Instit., vol. xxii., 1892, pp. 93, 94). 



In "The Ground Beneath Us," 1847, pages 71-79, many 

 interesting points bearing on this subject were already illustrated 

 and explained by Professor Prestwich. The great changes of 

 land-surface in this part of the European area were referred — 

 firstly to the movements, accompanying the elevation of the 

 Pyrenees, when the Chalk became dry land, with its uplands, valleys, 

 and estuaries ; and he showed that at that time the Wealden area 

 formed an island in the Thanet-Sands Sea. 



Some rivers afterwards brought down the clays and sands which 

 now constitute the " Woolwich and Reading " beds. With some 

 submergence other Tertiary beds were formed, probably extending 

 over a part of what is now the Wealden area. 



Secondly, this area, with its stratified coatings, was raised up 

 (after the formation of the London Clay) by movements accompanying 

 the elevation of the Alps by the lateral pressure caused by the earth's 

 contraction. The other Tertiary beds (of Paris, Bracklesham, etc.) 

 had helped to shallow the open sea surrounding the island of the 



* On one and the same specimen are some scratches quite raw, and some 

 that have been coloured with red cchre, also some merely linear streaks of red 

 hsematite. 



