76 



KNOWLEDGE cV SCIENTIFIC NEWS. 



[April, 1905. 



when it turns south, so as to include within it the whole 

 of Ireland. Then, following the same line still further 

 south, it is found off the entrance to the English 

 Channel, when, crossing the Bay of Biscay, it reaches 

 very near to the coast of Spain. It is when we pass 

 beyond the limits of this line that we find a compara- 

 tively rapid descent into oceanic depths. In fact, it 

 roughly represents the coast-line of the plateau-like 

 extension on which the British Isles stand, and is in 

 itself evidence of a great probabilitv that up to that 

 limit what is now the bed of the ocean was once dry 

 land. 



The changes which have since taken place form a 

 history of extreme interest, but it must be borne in 

 mind that great though the changes were, they were 

 extremely gradual in their accomplishment. After the 

 great plunge which had visited these islands in the 

 middle of what is known as the Ice Age. the area of 

 the North Sea had become a mass of ice, and this, 

 travelling westwards from the heights of Scandinavia, 

 had turned aside the numerous smaller masses of 

 moving ice which had been given birth to by the 

 Scottish mountains, and the heights of the Pennines 

 andWales. The result was that such parts of our higher 

 lands which were above the sea-level were submerged 

 beneath ihe ice-sheet, and the whole country must have 

 presented an appearance not unlike fireenland of the 

 present day. Possibly here and there the highest 

 points of our mountains projected through snow and 

 ice, forming prominences, or "nunataks," similar to 

 those seen by Nansen when crossing Greenland. But 

 at the height of the glacial period, probably even these 

 were covered, and right away from an elevated Scan- 

 dinavia the ice slowly moved westwards, and, over- 

 flowing our islands, passed on to break up into ice- 

 bergs in the ocean to the west and south-west. 



The submergence of the islands lasted, humanly 

 speaking, for a long period of years. From a geo- 

 logical point of view it lasted long enough to allow of 

 the formation upon the glacier-formed boulder-clay 

 of certain shell-bearing gravels; but as these are now 

 at heights of 1,800 or 2,000 feet above the sea-level, 

 there has apparently been, since these inter-glacial 

 days, an uprise of the land to that extent. Such shell- 

 beds are found near Macclesfield, at Moel Tryfaen, 

 and on the shores of the Clyde. 



We are here therefore presented with the fact that 

 an enormous elevation of the land took place, and that 

 this happened after both sea, and what little land there 

 was left, had been submerged beneath the great ice- 

 sheet. 



Apparently by this time a decline had set in so far 

 as the severity of the climate was concerned. The 

 glaciers in our own mountain regions commenced to 

 reassert themselves, this being only possible when the 

 Scandinavian intruder commenced to retire. There 

 was no longer a sea of ice. Switzerland or the Hima- 

 layas would give us a truer picture of our country at 

 this time, when the glacial conditions were on the 

 wane. 



.Many of the boulders which are now scattered about 

 far from their place of birth may have taken their 

 journeys at this time; or those that had journeyefl 

 during the period of the first formed boulder-clay 

 may now again have been taken up by the recurring 

 glaciers, and sentenced to retransportation. The great 

 lumps of shap granite that one sees at Robin Hood's 

 Bay and at Heyburn Wyke, or in the churchyard at 

 Orosmont, may have been brought to rest now, far 



from the home of their birth in the Westmoreland 

 Hills. 



The re-elevation of the land must have had marked 

 effect upon the coast-line. Probably the movement 

 went on until the coast was thrown outward to the 

 loo-fathom line, and our country was but a central 

 portion of the great plateau then exposed. There was 

 no English Channel left, and hence the Channel Islands 

 and our own Isle of Wight were continentally con- 

 nected. The Bristol Channel was non-existent. There 

 was no St. George's Channel between Ireland and 

 Great Britain. The Hebrides, the Shetlands, and 

 Orkneys were all part of the land-mass, and the North 

 Sea was non-existent. 



In the centre of the North Sea there was at this time 

 an area of about 300 square miles, which was con- 

 siderablv higher than the surrounding North Sea Plain. 

 This was situated some 100 miles off our present 

 Northumbrian and Yorkshire coasts, and what is now 

 left of it beneath the sea is the famous Dogger Bank. 



On the whole, this plain must have been a wide, dull, 

 and uninteresting flat extent of land, but although it 

 had but few heights, it was eminently suitable to be 

 the habitat of herds of wild animals. For, in the 

 course of time, the ice passed away completely, forests 

 grew upon the land, with pasturage suitable for the 

 vegetarian livers who swarmed upon it. This was at 

 the time when the British elephant was in his prime. 

 I lerds of bisons roamed over it. Crowds of reindeer 

 and Irish elks added picturesqueness to the landscape. 

 And in the waters and rivers the woolly rhinoceros 

 and the hippopotamus disported themselves. 



But what of the rivers which watered the land ? 

 Where did the rivers of Germany turn to in order to 

 find an exit into the sea? Where went our Thames, 

 our Severn, and our southward-flowing rivers? 



There being no English Channel, a river which rose 

 in the submerged \\'ealden area between Hastings and 

 the French coast no doubt passed westward to the 

 ocean, receiving on its way as tributaries the rivers on 

 the French and English coasts. The Severn and a 

 river from the Irish Sea may have joined to form 

 another such river, and this may have also joined the 

 Channel stream. Our Neolithic progenitors, in coming 

 to us from the Continent, would have had to cross this 

 river, but with the many monuments which they have 

 left of their civilisation this would not probably have 

 caused them any dilliculty. For the greater part their 

 journey would have been on dry land. 



The German rivers no df)ubt excavated their own 

 valleys across the plain and emptied thcmsehes into 

 the northern ocean. 



But what became of the great Rhine? As it now 

 emerges into the sea, it seems to point to the west. 

 But it could scarcely have continued in that direction, 

 for the parallel ranges of chalk downs were then 

 existent between the luiglish and French coasts, and 

 these would be sufficient to turn the river northwards. 

 There is little doubt, in fact, that it travelled north, 

 some little distance off our British coasts, and that the 

 Thames and all our eastward-flowing rivers formed 

 tributaries on its left bank. Some of the most im- 

 portant fishing grounds now seem to be in the valleys 

 scooped out by this long-ago greatly-extended Rhine. 



This condition of iiffairs did not last long in geologi- 

 cal time. The sea had for some time been creeping 

 up the English Channel and forming raised beaches at 

 Freshwater, Brightr)n, and elsewhere, and, when Scot- 

 land and Northern England began to sink, together 

 with the North .Sea Plain, the sea began to encroach 



