12 PEOCEEDINGS OF BROOKLYN MEETING. 



narrow, sharp channel. In the valley south of this there is no indication of an 

 esker; but, passing over the next elevation of till, a large mass divided into three 

 summits, there are indications of erosion in the main valley, and then on the 

 south slope there is a cirque-like hollow, which appears to have been excavated by 

 a fall of water, as in a moulin. From the mouth of this runs an esker, having a 

 height varying from 4 or 5 to 30 feet, which continues for a half mile, except where 

 cut by a brook. With a few breaks, a line of eskers can be traced in this same 

 linear direction as far as Hopkinton, a distance of ten or more miles. This shows 

 a general line of glacial drainage to have existed in this direction. Directly north 

 of Gleason's hill no eskers have as yet been found, though prominent ones exist 

 both to the northwest and northeast. 



At North Leominster, directly east of the station, is a large mass of till, which 

 forms a common base, upon which rest some ten or eleven summits of various 

 degrees of perfection. The largest channel yet seen is eroded out of the west end 

 of this mass. The depth of this channel has not yet been measured, but it is prob- 

 ably between 80 and 100 feet. The width is correspondingly great, as the sides 

 have not a very steep inclination. Here the amount of the material eroded is very 

 large, yet so far no evidence has been found of its deposition elsewhere. The mouth 

 of the channel opens directly toward the Nashua river, which is but a short dis- 

 tance away. It is probable that the detritus was carried into the floods which then 

 filled the valley and by them was swept away, to be deposited farther down stream. 

 This channel rises in a depression at the summit of the till mass and flows south- 

 ward with a winding and gradually broadening course. The inclination of the bed 

 is greater than that at Rockbottom. From the north side of the same depression 

 from which this has its origin another passed down the north side, but this is more 

 valley-like in appearance and has much less the characteristics of an erosional 

 form. In this case no eskers seem to be connected with the channels. 



Nortliwest of Worcester are three drumlius, not in direct line, each of which is cut 

 by a channel and between each two of which are portions of eskers so arranged 

 that the channels and eskers together form a nearly continuous serpentine line. 

 The evidence seems to imply some kind of a connection in the origin of the esker 

 and these channels. May not the same stream that produced the esker in one place 

 have cut the channel in another? If a stream, either superglacial or englacial, 

 were flowing on an ice-bed, material would accumulate in portions of its bed which 

 subsequently formed the esker, but finding a mass of till, a more resistant material, 

 in its course the action becomes then one of erosion instead of deposition, a chan- 

 nel is cut, and later, as the ice disappears, the esker is left in relief north and south 

 of the channel, which is a representative of the same force. 



About 300 channels of various sizes have been noted, but only in a few cases has 

 time allowed for more than a hasty glance at each. As stated above, only a very 

 small per cent of this number slope to the north; it is necessary to suppose in all 

 these cases, as in the one at Rockbottom, that the ice-sheet lay pressed against the 

 north side or end. What may have been the condition to the south is difficult to 

 determine. It may have been that there the ice had entirely melted and that the 

 front of the sheet was at the north of the hill, or it may be that melting had taken 

 place directly over the southern slope of the hill, and that here the stream simply 

 passed below the ice surface to become subglacial. Possibly further observations 

 may clear up this point. 



