398 E. Hitchcock on a Bowlder in Amherst, Massachusetts. 



shape, the four longest sides being nearly at right angles to each 

 other, while the ends were more irregular. Its medium length 

 was 6-J feet ; its breadth, 5-J feet ; and its thickness, 2f feet. 

 Consequently its weight was about eight tons. It was determined 

 to raise it out of its bed ; and when this was done, I was sur- 

 prised to find the striae more distinct upon the bottom than any- 

 where else. They were more minute upon the perpendicular 

 sides than on any other part, though these sides were perhaps 

 the most perfectly smoothed. But on all sides they were essen- 

 tially parallel, although upon the top there were at least two 

 sets, making a small angle with each other, as is common upon 

 surfaces striated by the drift agency. 



I had never met with a bowlder of this description. Its 

 unique character awakened an ambition in the class to remove 

 it entire. I doubted their ability to do this : but young men are 

 strong, and in this case they were very skillful also ; for al- 

 though much of the way is ascending, they went through the 

 work successfully, and without accident ; and in a single day 

 they planted- the bowlder in front of the Wood's Cabinet on a 

 slope, sustaining the lower end by portions of two large trap 

 columns from Mount Tom, so that the visitor can look beneath 

 and see the striae there. It stands in the same position as ori- 

 ginally, except that the ends are inverted. Deeply engraved 

 upon one end are the words, — " The Class of 1857 ;" that being 

 the year when they graduate. 



This rock is a fine-grained hard reddish sandstone, such as oc- 

 curs on the west face of Mettawampe, (Mt. Toby,) a mountain 

 lying nearly north of Amherst, ten miles distant, and from 

 which the bowlder was undoubtedly derived. 



How now shall we explain the parallel striation on four sides 

 of this bowlder ? Striated blocks I believe, have generally been 

 regarded as having been frozen into an iceberg, or a glacier, 

 which grated along the surface. But this explains the striae only 

 on one side. For if the bowlder should happen to have been 

 frozen into a second iceberg, or glacier, how small a chance 

 would there be, that it would be scratched in a parallel direction 

 on a second side. Far less is the probability that a third side 

 would have been striated in the same direction ; and almost in- 

 finitely less the chance that a fourth side would have experi- 

 enced a like dressing. Should a bowlder be frozen four times 

 into a mass of ice, how almost certain that the striae would run 

 in different directions. We must, therefore, give up the idea 

 that this bowlder was scratched in the manner usually assigned. 



But suppose that when it started from Mettawampe on its 

 southern journey, it were frozen into the bottom of an iceberg. 

 As this grated over the rocky surface, it would soon be smoothed 

 and striated : nor is it strange that in such a manner the erosion 



