THE CAMP-MEETING CUTTING. 677 



stream which occupied this lobe of the vahey, and whicli left lake bottom 

 and border alike intact on the recession of the waters. Over this region it 

 seemed more convenient to discuss them together, as has been done above. 

 (See p. 650.) 



THE SPRINGFIELD LAKE BOTTOM. 



On the east side of the river, at Smiths Ferry, south of the great Dry 

 Hill bar, and again much farther south, across West Springfield and Agawam, 

 are limited areas occupying a level considerably below that of the high 

 terrace or filled portiou of the lake, connected with it by a plainly marked 

 scarp of deposition, and on the other side separated from the later terraces 

 by an equally well-marked scarp of erosion. To these I have assigned on 

 the map the same color as that given to the lake bottom in the nortliei'u 

 lakes. They are, however, of so limited extent that the lake may be fairly 

 contrasted with the more northern ones as a filled-up lake, in so far as its 

 northern half in Massachusetts is concerned. 



DETAILED SECTIONS OF THE TERRACES AND LAKE BOTTOMS, SHOWING 

 SEVERAL ADVANCES OF THE ICE FRONT. 



THE CAMP-MEETING CUTTING. 



The cutting of the Canal Railroad, made in December, 1880, through 

 the plain on the north line of Northampton, at the northern edge of which 

 the Methodist camp-meeting grounds, called Laurel Park, are situated,^ was 

 at once the most complicated and, for the information it gave concerning the 

 oscillations of the ice, the most instructive of all those opened in the valley 

 of late 3'ears. It extended, with an average depth of 20 feet, for 3,250 feet. 

 I studied it with great care during the progress of tlie work and took many 

 sketches of all parts of it. I found the winter time in one respect verj- favor- 

 able for the study of these walls of incoherent sands and clays, as in the 

 steady cold they remained vertical for a long time and "weathered" like 

 banks of sandstone and shale, bringing out many refinements of texture 

 which would othei'wise have been overlooked. It was like an anatomist's 

 "frozen section." The cutting aftbrded two sections 50 feet apart, and after 

 its completion the steam shovel was put into the bank both to the right and 



' This cnttius; is J nst west of the a)iex of the great Hadley bend of the Connecticut, where the first 

 road crosses the railroad. 



