170 BOARD OF AGRICULTURE. 



glacier forms such a transverse wall of loose materials at its very- 

 termination. Now such transverse terminal moraines I find 

 along this valley ; one at Meyringen, another over opposite, 

 just across the valley, another at the Hospice of the Grimsel, 

 another about a mile from the termination of the glacier, and 

 one at the very termination of the glacier, showing the succes- 

 sive positions which the glacier has occupied. It is now in such 

 a condition that its termination remains about stationary. Near 

 by, the glacier of the Rhone is more influenced by the inequality 

 of the temperature of successive years, so that one year the gla- 

 cier advances and another year retreats. In consequence, we 

 have, at every termination of the glacier of the Rhone, one of 

 these concentric moraines, thirteen in all, close one upon another, 

 the farthest of which shows no sign of vegetation ; the second 

 has a few herbaceous plants growing on it ; the next a few 

 shrubs ; the next a few trees, the size of which indicates about 

 two centuries of growth, showing that about two centuries ago 

 the termination of the glacier was at this point ; and we know 

 from history that there was a very severe period, when glaciers 

 could advance much further than now. Since then it has been 

 alternately advancing and retreating, until it reached the place 

 where it remains now. 



In order to have reached twenty-one miles further down than 

 its present termination, the glacier of the Aar must have been 

 thicker than it is now. It terminates about six thousand feet 

 above the level of the sea, and there the polish is very fresh ; 

 but just above it you see that the wall of the valley is also pol- 

 ished and scratched, and as you go lower down you trace this 

 same polish upon the same side of the valley, to a greater and 

 greater height ; so that at Meyringen the level at which the walls 

 of tlie valley are polished is five thousand feet above the bottom 

 of the valley ; which shows that there was a time when the 

 glacier of the Aar, which is now only a thousand feet thick at 

 its thickest part, and less than three hundred feet thick at its 

 lower end, was five thousand feet thick, and for the whole length 

 of that you have the surface of the valley polished, scratched and 

 grooved ; and wherever the walls exhibit inequalities you find 

 that on those little terraces there are lateral moraines accumu- 

 lating. These lateral moraines begin at a level of nine thousand 

 feet above the bottom of the valley, and there are others at a 



