M. Renoir on the Glaciers of the Votges, 281 



opinion could not modify mine ; and it was almost with regret 

 that, in the month of July last, I made a first examination 

 round the ballon., and in the valley of St Amarin. This ex- 

 amination somewhat modified my former notions, and gave 

 rise to some uncertainty, which made me feel the necessity of 

 studying existing glaciers more particularly. The Society 

 will permit me to enter into a few details in this place, in 

 order to shew the process through which I went to establish 

 my convictions. 



We now know, from what has been pointed out by Messrs 

 Venetz, Charpentier, and Agassiz,* that the marks which gla- 

 ciers leave behind them as they retire, are, 1*/, Terminal mo- 

 raines^ composed of sand, gravel, pebbles, and even at times 

 a great number of boulders, the whole more or less rolled, 

 forming banks and curved lines throughout the whole width 

 of the valley, whose concavity is turned upwards, higher 

 towards the middle than towards the extremities, of a tri- 

 angular form, and having the exterior face generally more 

 inclined or steeper than the interior. 2^/y, Lateral moraines, 

 nearly of the same composition as the former, but arranged 

 in longitudinal mounds, deposited on the two flanks of the 

 valley at the same height, two by two, following all the con- 

 tours of the windings, entering every sinuosity, and having an 

 inclination which represents that of the surface of the glacier. 

 3G?/y, Median moraines^ resulting from the junction of the la- 

 teral moraines of two glaciers uniting. These moraines pre- 

 sent the form of a triangular prism, whose axis is in the di- 

 rection of the valley, and the nearer its middle, the nearer the 

 size of the glaciers approaches to equality. Athlt/, Whenever 

 the nature of the rocks permits, the bottom and sides of the 

 valley exhibit perfectly polished surfaces, together with par- 

 ticular indentations, in the direction of the glacier's motion ; 

 also stricB, or fine parallel lines, likewise running in the same 

 direction, that is to say, in the direction of the valley's in • 

 clination, but never following the greatest inclination of its 



* Many of the memoirs illustxative of this subject have appeared in the 

 previous numbers of this Journal. — Edit. 



