Cascade and Belloi^s-Pipe 221 



We now arrived at Crystal Spring, where we fresh- 

 ened up before entering the City in the ' ' hollow vale ' ' 

 three miles below. 



The formation of the Notch Valley was brought 

 about by one of the successive terminal moraines flow- 

 ing from the glaciated slopes of the ice-mountains 

 farther northwestward, in the Adirondack region; 

 while later the glaciated shoulders of Greylock's 

 Brotherhood slowly melted, eroding the slopes with 

 small ravines in which the numerous rivulets flow to- 

 day. The continental ice rivers from the higher glaciers 

 northward apparently culminated in tremendous and 

 successive cascades above Notch Valle}^ eroding the 

 deep-cut gorges between Greylock and Ragged Moun- 

 tains. The general directions of these currents, below 

 these waterfalls, were various, finally leading down to 

 the ancient Hoosac Lake, and flowing with it through 

 the natural dam, northwestwardly, to the Hudson 

 Valley, and thence to the sea. According to Professor 

 T. Nelson Dale, an ancient lake six hundred feet deep 

 existed in the Hoosac Valley ten thousand years ago. 

 Perhaps ten times ten thousand years ago, a greater 

 glacial sea overflowed the Hoosac Tunnel Mountains, 

 leaving the bald summit of Greylock alone towering 

 above the waves. As the terminal moraines of the 

 great ice-sheet slowly receded, the various cascades 

 formed pot-hole erosions, in their descent on the Canaan 

 Hills, above the Connecticut Valley. Deerfield Arch 

 was similarly formed by the force and chemical action 

 of the eroding ice rivers, which flowed from glaciers, 



