130 DISCUSSIONS IN CLIMATOLOGY. 



himself. In a section on alternations of warm and 

 cold periods during the Glacial Epoch * he says : — 



"The evidence that such was the case" (alternate 

 warm and cold periods) "is very remarkable. The 

 ' Till/ as we have seen, could only have been formed 

 when the country was entirely buried under a large 

 ice -sheet of enormous thickness, and when it must 

 therefore have been, in all the parts so covered, almost 

 entirely destitute of animal and vegetable life. But 

 in several places in Scotland fine layers of sand and 

 gravel, with beds of peaty matter, have been found 

 resting on ' Till/ and again covered by ' Till.' Some- 

 times these intercalated beds are very thin, but in 

 other cases they are twenty or thirty feet thick, and 

 in them have been found remains of the extinct ox, 

 the Irish elk, the horse, reindeer, and mammoth. Here 

 we have evidence of two distinct periods of intense 

 cold, and an intervening milder period sufficiently 

 prolonged for the country to become covered with 

 vegetation and stocked with animal life." 



Let us now see to what all this leads. It has been 

 proved beyond the possibility of a doubt that, at the 

 time the Till was being formed which overlies the 

 Scottish interglacial beds, the whole of Scotland, 

 Scandinavia, the bed of the North Sea, and a great 

 part of the North of England were covered with one 

 continuous sheet of ice upwards of 2000 feet in 

 thickness. This sheet overwhelmed the Hebrides, the 

 Orkney and Shetland Islands, extended into Russia, 

 filled the basin of the Baltic, overflowed Denmark and 

 Holstein, and advanced into North Germany as far at 

 least as Berlin. It has also been demonstrated that, 

 at the time the Lower Till was being formed which 

 underlies these interglacial beds, North-western 



* " Island Life," p. 114. 



