178 BOARD OF AGRICULTURE. 



been formed by the partially thawing snow. Now, a mass of ice 

 formed in this way is constantly changing its relations to its 

 parts ; and upon a slope, in consequence of this change of parts, 

 it is moving, and it is moving at a rate which is quite consider- 

 able. I will take the facts as they are in the Alps, where you 

 may see along the slopes of the Alpine valleys, the onward 

 movement of such masses of ice, resulting from the transforma- 

 tion of the snow in the higher regions into ice. That motion 

 may be two or three hundred feet a year ; it may be less or 

 more, according to circumstances ; but there are conditions 

 which determine the rate of this movement. 



Now let us consider one particular case, so that we may have 

 these facts very clearly before us. There are in Switzerland 

 three chains of mountains, about the same distance apart — the 

 Finster-Aarhorn, the Schreckhorner, and the Wetterhorner. 

 Upon the slopes of each of these mountains, there is a large 

 accumulation of snow. Suppose, at one point, we have nine 

 thousand feet above the level of the sea. Above this level, all 

 these masses of snow retain, more or less, their character of 

 snow. The level is too high for frequent thawings to take 

 place ; too high for rains to fall, or for the moisture in the 

 atmosphere to fall, in any form except snow. I have, at that 

 elevation, witnessed a fall of snow, in the early part of August, 

 which left, as the result of one night's fall, two feet on the 

 ground. You see, therefore, that when it rains in the lower 

 regions, we have snow in these higher regions, and that snow 

 has not so frequent chances to pass into ice as it has lower 

 down, where the temperature being higher, there are more 

 frequent oscillations above and below thirty-two degrees. At 

 this point, the temperature is very constantly below thirty-two 

 degrees. Lower down, about the level of six or seven thousand 

 feet, there are frequent alternations above and below thirty-two 

 degrees. Further down still, say at five thousand feet, the 

 temperature is, during summer, always above thirty-two de- 

 grees, and only during winter below thirty-two degrees; so 

 that we have the most diversified climatic conditions in . a. dis- 

 tance which is small, but which is made great, practically, by 

 the difference in height. "We have there, without travelling 

 more than an hour or so, differences which amount to the 

 difference you observe when, starting from here, you go to 



