CHAPTER III. 



CONXERNING EARLY FLOODS. 



There is at this flay no excuse for descendants of our Derry- 

 field ancestors not knowing that a literal river of ice once flowed 

 down the now peaceful valley of the Merrimack. Its direction, 

 volume and extent are mapped upon their rock-wiinkled home- 

 steads. It crawled southward, grinding- along at the rate of 

 a foot a week — a mile in a century. It at some time halted, 

 for how long we may oidy guess, and then began the terrible 

 retreat. The rate of recession is not so well determined, but 

 was without doubt comparatively rap'd, though probably arrested 

 at various stages and for undefined periods. To judge from the 

 wide-s|ircad havoc to which this near section has been subjected 

 tiiere must have been a halt near us. We know — since we 

 stand upon the scene of the event — that from the foot of this 

 retreating, melting glacier, poured frightful down-rushes of tur- 

 bid water, by whose action the landscape acquired its present 

 characteristic leatures, and by which the suiface materials of 

 this region have been so strangely sifted and assorted. 



The touii.stof to-day who shall stand beside the source of the 

 Arveiron, " who drinks in the sublime view at the foot of the 

 glacier ; he wlio beholds this marvel, glorious with icy portico, 

 facade and pyramid, who hears at night the scornful roar of the 

 Alpine flood," may peradventure frame some dim conce[jtion of 

 energies which seem to know no yesteiday nor morrow. But 

 greater things than these, which promised to flow forever, have 

 passed away. 



Let us come nearer home. Passing westward from the river 

 let us climb the isolated ridge of Rock Rimmon — if, indeed, it 

 be not also submerged — and from that point observe. To the 

 west and trending northerly lies the valley of the Piscataquog ; 



