and " Roches Moutonne.es." 491 



Again, about half a mile west of Staveley, on the south side 

 of the Ambleside road, upon the upper surface of a quarry 

 which slopes to the north, very perfect furrows and striae are 

 seen running about S.E., and the surface is rounded and 

 polished. A portion of an elliptic boss was noticed, showing 

 that before the rock was quarried so far, there had existed a 

 highly illustrative example of the "roche moutonnee." By 

 the further removal of the superficial detritus, similar markings 

 will no doubt come into view. 



VI, Theory of the Markings. 



Pursuing this inquiry in company with the gentlemen before 

 mentioned, the Ambleside and Grasmere vales were traversed 

 as far as the summit of Raise Gap ; and the upper part of the 

 valley running thence northwards as far as the head of Thirl- 

 mere, with the whole western flank of Helvellyn, without 

 noticing further cases. Our examination was, however, rather 

 cursory; a closer investigation would probably have detected 

 additional examples. It is highly desirable that the valleys 

 descending to the N.E. and N.W., and opening towards Pen- 

 rith and Cockermouth, should be carefully examined with 

 reference to the existence of such markings. Their discovery 

 in these valleys, in connexion with the facts stated in this 

 communication, would throw much light upon the history of 

 the superficial deposits of the lake district, and the nature of 

 the forces by which the great masses of transported materials 

 filling the outer valleys and the plains at the base of these 

 mountains were brought into their present situations. In a 

 series of most able papers, supported by mathematical rea- 

 sonings and calculations, Mr. Hopkins has undertaken to 

 show that the lake mountains have been raised to their pre- 

 sent height by many successive elevations of a paroxysmal 

 character ; that these gave rise to great " waves of translation " 

 and diverging currents of enormous power; so great, for ex- 

 ample, "that an elevation of 100 or 150 feet would produce a 

 current capable of transporting, for at least a short distance 

 and under favourable circumstances, a block of immense 

 weight/' and consequently lighter materials to great distances*. 

 During the periods of repose the action of the sea would 

 scoop out valleys near the centre of elevation, and hence the 

 great system of diverging valleys which run from the central 

 group. This operation would be determined in the first in- 

 stance, and greatly facilitated in its progress by the prior ex- 



* Trans. Camb. Phil. Soc. vol. viii. part 2; Journal Geol. Soc. vol. iv. 

 p. 70. See also a valuable paper by Prof. Whewell, Journ. Geol. Soc, 

 vol. iii. p. 227. 



