330 Proceedings of the Royal Physical Society. 



Cumbrian Lake Country must have flowed outwards freely 

 in many directions, which they could not afterwards follow 

 when the united mer dc glace came to fill up the basin of the 

 Irish Sea and advance inland upon Cheshire, etc. At the 

 period of maximum glaciation the path of the ice would 

 often be at right angles to what it was before that maximum 

 was reached, and to what it again became after the mer de 

 glace was on its final decline." 



Mr Jamieson states in his paper that where he observed 

 f'any indication of a stoss-seite it was on the north-west side."* 

 But no instance is quoted save one about two miles south of 

 Berriedale where some masses of conglomerate " crag " to the 

 east, as if produced by ice moving seawards. This example 

 is situated at the southern margin of the shelly drift, and 

 was evidently caused by the local ice already described. 



The absence of any well-marked roclies wmUonnees in the 

 area occupied by the shelly drift may be satisfactorily 

 accounted for by the peculiar mode of weathering of the 

 Flagstone series. The flagstones were not capable of assum- 

 ing the dome-shaped contours so characteristic of highly 

 glaciated regions. In many instances they broke up into 

 subangular blocks underneath the ice, a striking example of 

 which has already been described in the Achscrabster 

 quarries. The very same features we found to obtain in 

 Orkney in the tracts occupied by this series. But notwith- 

 standing this mode of weathering, we have adduced several 

 examples which indicate a movement towards the north-west, 

 and when these are viewed in connection with the remark- 

 able deflection of the local ice-stream, it must be admitted 

 that the evidence derived from the striated surfaces and the 

 roches moutonn4es is clearly in favour of this conclusion. 

 This view receives additional support from the evidence 

 supplied by the boulder clay. 



IV. Boulder Clay. 



Within the county this deposit is of two distinct types, 

 corresponding with the two opposing streams of ice just 

 described. We have (1.) a stiff, dark grey, shelly boulder 



* Quart. Jour. Geol. Soc, vol. xxii., p. 268. 



