426 GLACI4L GEAYELS OF MAmB, 



Of the longer meauderiiigs, all that can be said is that they are trans- 

 verse to any known direction of flow of the ice. 



Meanderings of the second class are short — from a few rods to a large 

 fraction of a mile. They are such as might be produced by either kind of 

 stream. They are plainly such as would characterize the channel of a 

 superficial stream. On the other hand, a subglacial stream would often 

 follow a transverse crevasse for a short distance, and thus could flow trans- 

 versely to the glacier. It is not certain how far it could thus find its way 

 transversely. So, also, in the northward extension of a subglacial tunnel 

 its course might often consist of short zigzags caused by its attempt to 

 follow a superficial stream in a direction transverse to the glacier. 



In general it may fairly be urged that many of the meanderings must 

 have been formed simultaneously, and that some of them must have been 

 transverse to the glacier. Now, though ice is protean in its resources, it 

 can not be all things at the same time. The osars of Maine skirt too many 

 hillsides and cross too many valleys of natural drainage to permit the 

 admission that the subglacial waters coiild everywhere penetrate the ice 

 transversely to the direction of ice flow. The probabilities are overwhelm- 

 ingly against the hypothesis. For subglacial waters to flow transversely to 

 the motion of the ice must have been the exception rather than the rule in 

 Maine, except near the ice front, where the ice was much crevassed. Near 

 the great outer terminal moraines and in the tracts of reticulated ridges or 

 kames the ice was so crevassed that probably the subglacial waters could 

 make their way so as to practically follow the slopes of the land. 



The longer meanderings transverse to the direction of ice flow certainly 

 add some difficulties to the hypothesis of subglacial streams. 



PINNACLES OR ELONGATED CONES. 



On the theory of subglacial streams the "pinnacles" or elongated 

 cones which here and there rise above the rest of an osar can be accounted 

 for as having been deposited in an enlargement of the subglacial channel, 

 such, for instance, as forms at the base of the cascade where a superficial 

 stream plunges down a crevasse into a subglacial tunnel. On the theory 

 of superficial streams they could be explained as having been deposited in 

 the broad pool that formed where a lateral tributary joined the main stream, 

 or in one of the numerous pools that would form at the base of waterfalls 



