146 
channels, resembling the modern shore in this respect; or over 
areas where there is at least evidence that the till has been sub- 
jected to the sorting action of water and the finer materials 
removed. It is reasonable to suppose that the bowlders are 
most abundant in the lower parts of the drumlins, and in gen- 
eral where the till is thinnest, as may be observed at many 
points over the rocky peneplain of Cohasset ; and it is certainly 
not improbable that, as suggested to me by Mr. Upham, this 
is owing, not wholly to the fact that the source of the bowlders 
is near at hand, but partly to an actual combing of bowlders 
out of the till or ground moraine as it was swept past the 
ledges by the movement of the ice, the ledges thus serving as 
gathering points for bowlders. 
An oceasional bowlder merits special attention on account of 
its size; and some of these are rather striking also in their sit- 
uations. As might be expected, the largest erratics consist 
almost exclusively of granite, the most massive and resistant 
rock of the region. Опе of the most impressive examples 
observed in the Nantasket-Scituate area is the block of granite 
on Booth Hill, in Scituate, known as Hatch’s Rock (Fig. 23). 
It is very regular in form, approximately twenty feet square 
with ап average height above the ground of at least ten feet. 
It stands on. the summit of the hill and some fifteen feet above 
a broad level terrace or platform. Near the eastern base of 
Booth Hill, on the grounds of Mr. Silas Peirce, is Toad Rock, 
a block of diorite about twenty feet long resting on a local 
deposit of modified drift. 
A granite bowlder about twenty feet long, twelve feet wide, 
and ten feet high lies in the woods close on the south side of 
Beechwood Street, about one mile northwest of Beechwood 
Village, with several others nearly as large near it; and east 
of the Village a block of granite which is approximately a ten- 
foot cube lies on the west side of Bound Brook, a few rods south 
of the street ; while in the rocky woods south of Scituate Hill 
may be found a striking example of a large bowlder which has 
been disrupted by the action of the frost. 
