HOW THE SOIL CAME. 37 



when the glacier left them is very clearly seen when the 

 protecting coat of soil is removed, showing the smooth 

 rounded hummocks. The making of roads and other ex- 

 cavations have exposed the scratches in many places now 

 to be seen. 



On South Main Street, the highest point of the ledge in 

 front of Mr. Welch's stone wall, the lines are seen run- 

 ning parallel with the road. Judging from the lichens that 

 have grown in these marks, the protecting soil might have 

 been removed at the very earliest period of white inhab- 

 itants. 



Another exposure very recent is on Jerusalem Road 

 within a few inches of the easterly wheel track on the 

 summit that lies between the HoUingsworth and the 

 Richardson estates. Again on Jerusalem Road near the 

 Black Rock House and along the south side of Straits 

 Pond the marks are to be seen. On Cedar Street, where 

 the road was widened last year, some clear glacial striae 

 were exposed to the eye upon both sides of the road in 

 several places. Where they have scratched across a dia- 

 base dike by the edge of this road the lines are beautifully 

 clear cut. 



But further enumeration is needless, for any man may 

 find them in his own dooryard by peeling off the garment 

 of soil. 



The stones which did the scratching can be captured, 

 many of them, in the gravel and hardpan, those that did 

 not have time to escape to the sea. 



One huge graver is now a perched bowlder, Bigelow 

 Bowlder,* standing exactly in his last grooves on the ledge 

 a half mile west of King Street at Sohier. 



By crawling under it one can place his hands in the smooth 

 grooves just as they were left seven thousand years ago. 



* This bowlder has been known by the inhabitants of King Street as Tipling 

 Rock; but the Committee upon Town History lias named it after the writer, to 

 avoid confusion with the Tipling Rock in the Wheelwright estate. 



