Professor Forbes on the Leading Phenomena of Glaciers, 221 



beautiful appearance, quite new to me. The heavy snow of 

 the previous winter had not been entirely melted during the 

 whole summer, and still lay in all the hollows where it could 

 accumulate. A series of snowy bands having this origin ap- 

 peared at regular intervals upon the upper part of the Gla- 

 cier du Geant, corresponding in distance and form to the ar- 

 rangement of the " dirt bands " in the lower part of the 

 glacier, as I have endeavoured to represent below : — thus as- 



Fig. 1. 



Rocks. 



'•'A- -••'•.« l.'"-. '•*■■.'?.*. .'••••! 



Rocks. 



certaining a most curious and unsuspected fact, namely, the 

 existence of a series of curvilinear hollows on the nearly plane 

 surface of the ice, which the eye would probably have in vain 

 striven to detect, but for the palpable evidence of the accu- 

 mulations of snow lodged in the intervals of these vast 

 waves. In Fig. 1. the ground-plan of a part of the Glacier du 

 Geant is shown, where it is divided longitudinally by the 

 Medial Moraine descending from the Aiguille Noire. The 

 left hand portion of the icy stream descending from the 

 ridge, called *' les Periades," bears that name. The masses of 

 dots indicate the position of the snow wreaths which mark 

 the indentations of the ice ; these appeared to be confined to 

 the ice of the proper Glacier du G^ant ; the lines indicate the 

 direction of the most distinct veined structure in the ice, which 

 are visible in a mass from a distance, as the finely veined 

 structure of Cipollino marble is, even when the laminae com- 

 posing it cannot be individually seen. The conclusion from this 

 IS, that the surface of a glacier is not an inclined plane, nor 



