Notice of Prof. Forbes' s Travels in the Alps. 189 



chain of Mont Blanc. The Pavilion de Bellevue on the Col de Belle- 

 vue, is nearly seven thousand feet above the sea, and yet erratic blocs 

 are strewed all around upon it. These erratic blocs mix insensibly with 

 the modern moraine of the glacier of Bionassy beneath, so that it is 

 impossible to say where the erratic phenomenon ends and where the 

 glacial phenomenon begins." 



A very striking argument in favor of the glacial theory of erratics 

 is thus presented on jthe spot, and these very blocs of protogine granite 

 continue for many miles down the country without any intermission. 

 The Lac de Combal is bounded by moraine ; it pushes along several 

 miles in length, nearly a mile in breadth, and several hundred feet deep. 

 " The old moraines are still fortified with slits for musquetry, probably 

 erected by the Piedmontese troops in 1794. It is strange to see this 

 application of the artificial looking mounds which the glacier has raised, 

 and which bear no slight resemblance to a series of gigantic outworks 

 of an extensive fortification." The moraines are here formed in the 

 shape of semilunar curves or crescents, of which there are four, with 

 their convexity up the valley ; and the outermost of these was occupied 

 as a fortification. "The icy torrent as it spread out in the Allee 

 Blanche, appeared to me to be three and a half miles long, and one and 

 a half wide. After struggling for a long time among fissures and mo- 

 raines, I at length mounted a heap of blocs higher than the rest, and sur- 

 veyed at leisure the wonderful scene of desolation, which might com- 

 pare with that of chaos, around me. The fissures were so numerous, 

 large and irregular, as to leave only a series of unformed ridges, like 

 the heaving of a sluggish mass, struggling with intestine commotion, 

 and tossing about over its surface, as if in sport, the stupendous blocks 

 of granite which half choke its crevasses, and to which the traveller is 

 often glad to cling, when the glacier itself yields him no farther pas- 

 sage. It is there that he surveys with astonishment the strange law of 

 the ice-world, that stones always falling seem never to be absorbed — 

 that, like the fable of Sisyphus reversed, the lumbering mass, ever fall- 

 ing, never arrives at the bottom, but seems urged by an unseen force 

 still to ride on the highest pinnacle of the rugged surface. But let the 

 pedestrian beware how he trusts to these huge masses, or considers them 

 as stable. Yonder huge rock, which seems ' fixed as stable Snowdon,' 

 and which interrupts his path along a narrow ridge of ice, having a 

 gulf on either hand, is so nicely poised, ' obsequious to the gentlest 

 touch,' that the fall of a pebble, or the pressure of a passing foot, will 

 shove it into one or the other abyss, and the chances are, may carry 

 him along with it. Let him beware too, how he treads on that gravel- 

 ly bank, which seems to offer a rough and sure footing, for underneath 

 there is sure to be the most pellucid ice ; and a light footstep there, which 



