426 



Glaciers. 



lake of more than five miles in length. In the fore- 

 ground, are the then unweathered block-strewn roches 

 moutonnees, on which Dolbadarn castle now stands, 

 which here and there are still marked by distinct 

 glacial striations. This scattering of boulders on the 



FIG. 90. 



Roche Noutonnee, with Sloes Perekes, Pont-y-gromlech, Pass of 

 Llanberis. 



bottom of the lake is analogous to that which now takes 

 place in the Marjelen See, or which on a great scale 

 once took place, as the mighty glacier of the Rhone was, 

 from where Geneva now stands, slowly retreating fifty 

 miles eastward towards Bex. In the shallow water 



