BOWLDERS. 559 



as due to the surface oxidation and disiutegTation b}^ frost. The same was 

 true at the Central Raih-oad cutting- south of the colleg-e, wliere beneath the 

 clays th(! till was in its upper part olive-green to brown, ami blue green 

 below, but with no further distinction in matter of compactness, coarseness, 

 or derivation of bowlders. I have seen several cases where the upper layer 

 was blue and the lower reddish. 



REMARKABLE BOWLDERS. 



President Hitchcock has described' and named six of the most notable 

 traveled bowlders to be found on the east of the river in tlu^ valhiv and on 

 its border, remarking that bowlders of the larg-est size do not occur in this 

 vicinity. Those named are: 



THE NORTHERNER. 



An irregular mass of the coarse conglomerate of Metawampe (MoiMit Tom), 

 weighing nearly 100 tons, * * * lodged on the gneiss rock of Pelliam Hill in 

 the bed of a large brook close by a small cascade, where it was pointed ont to me 

 by Mr. Newall. 



BOCK ORES. 



Near the top of Mount Warner, a little east of the summit and in the cleared 

 pasture, lies a large bowlder of imperfectly prismatic trap or greenstone. Its weight 

 we estimated at 78 tons. The rock of the mountain is granite and niica-scliist, and 

 no trap in place is found to the north till we reach the north part of Sunderland 

 and the south part of Deerfield, say some 10 miles distant. From that range this 

 bowlder undoubtedly came. * * * 



ROCK ETAM. 



Northwest of Rock Oreb, say a quarter of a mile in the woods, and fur down the 

 northwest slope of the mountain, is another and larger bowlder of the same variety of 

 trap. We estimated the weight of the Hadley Etam to be 385 tons. » * * 



Another bowlder of the same columnar trap projects from the ground on a lower 

 bench of the mountain southeast of Rock Oreb. Its exjiosed portion is half as large 

 as the latter. 



THE MAGNET. 



At the western foot of the steep part of Holyoke, and a little south of the place 

 where the railroad goes ui) the hill, lies a large bowlder of trai) precisely like those 

 just described on Mount Warner. It is 15 feet high, and, by a loo.se estimate, I 

 think it must weigh 300 tons. It is remarkable for exhibiting on its north face a 

 vast number of magnetic poles sufficiently strong to completely invert a common 

 magnetic needle, forming in fact several continuous lines of poles. I spent .some 

 days several years ago in tracing them out. These facts furnish a reason for the 

 name which I venture to propose for it, viz, The Magnet. I formerly supposed that 



' Remiuiscences of Amherst College, pp. 264-265. 



