STvaccs of tl)C (Svrat lice ^gc m ISctlJgsljitf. 



By George Fletcher, F.G.S. 



NY reference to the subject of the Glacial Epoch in 

 circles other than Geological, fail, we fear, to convey 

 any definite impression. Indeed it may be doubted if 

 people in general regard the ascertained facts respecting 

 the Great Ice Age as more than " speculations of so-called men of 

 science." Yet the evidence for the view — that at a period very 

 recent (geologically speaking) the whole of northern Europe and 

 America was buried under a huge and almost continuous ice- 

 sheet — is overwhelming ; indeed, it may be regarded as a fact as 

 well ascertained as that of the Roman occupation of Britain. A 

 study of the widespread deposits classed as " Drift " has taught 

 us not only that during this period intensely arctic conditions 

 prevailed in northern Europe, but that alternations of arctic and 

 temperate conditions took place, the directions in which the ice 

 flowed, and, approximately, to what limits. To quote the 

 words of Professor James Geikie, " it is hardly too much to say 

 that we are as well acquainted with the distribution of glacier-ice 

 in Europe during the Ice Age as we are with that of ex/sii//x 

 snow-fields and glaciers." 



To present the facts briefly : — Scattered over the surface of the 

 British Islands, as far south as a line extending from the Bristol 

 Channel to the mouth of the Thames, and occupying an area 

 of some thousands of square miles, is a deposit known to 

 geologists as //// or boulder-clay. It consists of unsiralificd 

 material — mainly clay, sand, and gravel — containing boulders of 

 all sizes, these being sometimes of the same kind of rock as that 



