GLACIAL DRIFT. 219 



boundary does not extend beyond New Hampton on the main stream, 

 passing instead to Newfound lake. The movement north of New Hamp- 

 ton belongs to another area quite distinct. It is thus like the Connecti- 

 cut glaciers, divided by a barrier above Monroe. As thus limited, the 

 Merrimack glacier is with difficulty separated from the general south- 

 easterly movement. The country is almost fiat below Concord, so that 

 there is little opportunity for a local glacier to exist for want of inclina- 

 tion ; and the western sloping valleys on the east side rarely show any 

 marks pointing westerly. From Winnipiseogee lake to Franklin the de- 

 scent is sufficiently great to induce motion, 225 feet in fifteen miles, but 

 the ledges are covered, and no topographical feature suggests glaciation. 

 Any special striation or embossment in the lower part of the Suncook 

 and Soucook rivers would be concealed by the immense piles of alluvium 

 of later origin. The upper Souhegan valleys are better adapted to show 

 these evidences ; and no situation could be better than that of the upper 

 Contoocook for exhibiting traces of the glacial action distinct from that 

 of the general drift. Warner river valley is much like the Souhegan. 

 Three of the more northern tributaries of the Merrimack show good 

 evidences of the valley movement, — Smith's, Blackwater, and the Pemi- 

 gewasset rivers. I will describe these first. 



SviitJis River. This stream rises at Orange summit, follows the 

 Northern railroad through Grafton and Danbury, and thence turns east- 

 erly between Alexandria and Hill. The course of the valley usually 

 corresponds with that of the general movement, but the phenomena of 

 embossment are like those of local glaciers. In the Orange summit 

 notch, the course is S. 36° E., a few more degrees easterly than is com- 

 mon in Canaan and the north part of Orange. It is the same at the 

 north end of Tewkesbury pond, but 5° less at the outlet. The rock 

 for several miles about is admirably adapted to exhibit striation and 

 embossment, and the phenomena at the outlet of the pond where 

 the railroad passes can hardly be excelled for perfection in an}^ part of 

 the state. Any one familiar with glacial phenomena would instantly 

 recognize them while passing in a train. At the mica quarries on the 

 west side of Grafton valley, the course is about the same ; also, at a 

 school-house between the two Grafton stations. We should expect 

 somewhat more easting at this point, as the course of the valley has 



