34 HISTORY OF C OH ASSET. 



These little glaciers joined forces in the valleys and 

 moved on, growing larger each year because the summers 

 were becoming less equal to the task of melting them. 

 By the end of a few thousand years, the weather grew so 

 cold all over New England that the trees were scrubby 

 and hopeless, the animals had disappeared to the south, 

 and the ice and snow inherited the land. Then followed 

 a period of a thousand years or more when each summer's 

 sun looked upon a field of arctic snow growing thicker 

 each year where now New England blooms. 



Some snow melted, but the remnant each year was 

 larger than the year before, and it kept building upward; 

 for the snow turned gradually to ice and much of the rain 

 froze before reaching the ground beneath. The annual 

 precipitation for this region is nowadays about forty 

 inches ; so that if all the yield of the clouds for five 

 hundred years became ice upon the surface of New 

 England, the thickness would have been considerably 

 more than one thousand feet. At some period of the 

 deposit this ice had to begin to slide, for the slope of the 

 land towards the water made its footing insecure, and it 

 was urged onward by the pressure of the mountain glaciers 

 behind. But the ice froze to the soil beneath it, and its 

 grip was made more secure by the freezing of whatever 

 water might have percolated through the ground in the 

 melting seasons, until the only way for the ice to move 

 was by dragging the frozen soil. 



The movement was slow, but the grinding between the 

 soil and the rock ledges was very fierce. By actual 

 measurement, the great Muir glacier in Alaska, at a place 



carries warmth from the tropics to the Northern Atlantic and Northwestern 

 Europe." — Appendix A in Wright's Ice Age, p. 584, Probable Causes of 

 Glaciation. 



Mr. CroU's illustrious and elaborate theory that the periods of eccentricity and 

 nutation of the earth constitute the main cause of the glacial epoch is not credited 

 now by the leading glacialists of America. The glacier was one hundred thousand 

 years too recent for that theory. 



