EDEN VALLEY AND YORKSHIRE-DALE DISTRICT. 93 



of the subject) universally understood, we meet with complete 

 failure. 



It does very well in cases where we have only to account for 

 the origin of an unstratified mass of stiff clay full of glaciated stones 

 whose longer axes are nearly parallel to the underlying rock-surface. 

 It is at least intelligible how a mass of ice which, at the foot of 

 Stainmoor, was certainly not less than 1200 or 1400 feet in thick- 

 ness, could cause to accumulate here and there beneath it thin de- 

 posits of tough clay and scratched stones which had been scraped 

 along between the ice and the rock- surface for many miles. But if 

 any one nowadays needs to be convinced of the power of such a 

 sheet of ice to crush up and contort any soft beds that lay in its 

 way, let him examine a few sections of alternations of hard and soft 

 beds that have lately been bared of drift, at almost any spot over 

 which the ice had a great thickness ; it will then be manifest that 

 these thin soft beds of sand and clay occurring interstratified with 

 the till, could not have escaped violent contortion. They would be 

 much more likely to be kneaded up into the clays until every trace 

 of their existence was lost, if the ice ever advanced a single inch 

 over them. 



It was mentioned above, that the far-derived boulders had hitherto 

 been met with only in the upper till, or in deposits that are pro- 

 bably referable to that horizon. Taking it for granted that the ice 

 that transported the Galloway boulders right across England to 

 the North Sea, and exercised enough denuding force to tear up 

 Brockram from the bottom of the valley of the Eden, and afterwards 

 transported it up the slopes of Stainmoor, must, if the moraine-pro- 

 fonde theory be entirely true, have had a much greater thickness 

 than the ice that was only capable of dragging its moraine jprofonde 

 a few miles ; it follows that it must have tended, more than the 

 hypothetical older ice-sheets, to crush and contort every thing that 

 could be thus acted upon from the surface. How then can we 

 account for the presence of entirely undisturbed beds of finely stra- 

 tified and incoherent sands, and sheets of laminated clays in and 

 beneath the upper till ? 



As the moraine-profonde theory fails to meet the requirements of 

 these cases, it is obvious that some other explanation, which shall 

 be more in accordance with the observed facts, must be looked for. 



The writer therefore ventures to lay before the Society a theory 

 that has suggested itself after a long consideration of Prof. Ramsay's 

 theory of Glacial currents, and a careful examination of a consi- 

 derable tract of country in the north-west of England by the light 

 of this theory. 



Most persons who have lately written on glacial subjects have 

 remarked how suddenly the great ice-period was brought to a close. 

 So little modification have the striae undergone at almost all eleva- 

 tions, that it is no uncommon thing to find the striae going right 

 across the bed of a considerable valley in such a way as to show 

 that, had the ice dwindled away by slow degrees, and passed back 

 through all the stages of glacier-development to the tiny glaciers of 



