202 



THE GEOLOGIST. 



tliem off, carrying away the debris to form tlie Tertiary mud and 

 sands, which in turn — uplifted, too, with the expanding ground — 

 were also partly sliced away, leaving the patches and remnants we 

 have observed upon the summits of those chalk downs, which record 

 the first act in the long period of denudation associated with the uprise 

 of the Wealden tract. Slowly in this way did the sea do its antago- 

 nistic work, until the inner domes of gault and greensand were cut 

 down to nearly level plains encircling one and another round the 

 central Wealden beds, which, like an island, stood out last in the 

 midst. 



Nor is the story ended now. England and France were then 

 united lands ; no " narrow straight" separated two nations of emula- 

 tive men, but the hairy mammoth, the giant elk, the thick-skinned 

 hippopotamus, and other of the great beasts of that marvellous age 

 of gigantic forms which preceded and joined on to the age of man the 

 ages of the irrevocable past wandered across and Kved and bred in 

 the forests, caves, or marshes of our land. 



Slowly as the intumescence proceeded, there opened out wider and 

 wider a long fracture through the uprising land, up which the sea 

 washed daily and nightly, with high swelling tides, that, pent up by 

 the cliff-walls of the crack, eddied back at ebb mth monstrous force, 

 and carved out at either end the triangular edentations which still 

 form the openings of the British Channel. Sweeping round in their 

 eddyings as restrained by the ridge of land that formed the barrier 

 to their onward passage, these pent-up tides scoured the Wealden 

 plains, and strewed the bases of the downs with half-worn flints and 

 gravel. To explain this more fully I have drawn a rough sketch of 

 the English Channel, with the narrow neck of land which may be 

 presumed to have existed there dui^ng at least the eai4y part of the 

 Pleistocene age. 



We all know that the great tidal wave striking the land at the 

 Lizard Point, in Cornwall, parts in two, or bifurcates, one tide msh- 

 ing up the Channel, the other swinging round the whole extent of 

 the coasts of Wales, Scotland, and the East of England, until it 

 meets and collapses with the Channel tide, off Pegwell Bay. 



In those geologic times to which we have referred, the narrow 

 isthmus which stretched across from Folkestone to Boulogne ban-edthe 



