40 



FIFTH LETTER ON GLACIERS. 



[1844. 



and still lay in all the hollows where it could accumulate. A 

 series of snowy bands having this origin appeared at regular 

 intervals upon the upper part of the Glacier du Geant. corre- 

 sponding in distance and form to the arrangement of the " dirt 

 bands" in the lower part of the glacier, as I have endeavoured 

 to represent below : thus ascertaining a most curious and un- 



Rocks. 



Fig. 6. 



suspected 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 pal- 

 pable evidence of the accumulations of snow lodged in the inter- 

 vals of these vast waves. In fig. 6 the ground-plan of a part 

 of the Glacier du Geant is shown, where it is divided longitu- 

 dinally by the medial moraine descending from the Aiguille 

 Noire. The 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 Geant ; 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 composing it cannot 

 be individually seen. The Conclusion from this is, that the 

 surface of a glacier is not an inclined plane, nor an inclined 



