134 SURFACE GEOLOGY. 
two places are only a few feet higher than that near the Pavilion. Nearly 
all that part of the village which lies south-east from the bridge is built 
on a thick mass of till, which encloses a continuous stratum of clay. 
North-east from the Pavilion a slope descends in about twenty-five rods 
to a small pond, which is tributary to the lake and of the same height. 
This slope has a surface of till, with numerous boulders; but excavations 
for brick-making show that the clay beneath has a thickness of fully 20 
feet, with its bottom resting on till only a few feet above the lake. The 
till on the surface is 1 to 8 feet deep. This clay is free from pebbles, and 
is finely laminated in its lower portion, while its upper part sometimes 
crumbles into small angular pieces. No deposits of clay appear to occur 
in the thinner till which covers the hillside north-west from the bridge. 
At Clay point in Alton, three miles south-west from Wolfeborough, 
the lake shore rises steeply from Io to 4o feet, and from the top of this 
escarpment the surface, which is coarse till, has a very gentle upward 
slope. The lower part of this bank consists of a stratum of clay which 
was worked forty years ago for brick-making. This was at the end of the 
point where there 
was at least fifteen 
Upper till. feet, and perhaps 
Clay, 15 feet or ; 
more. considerably more, 
Gravel, 2 feet. 
Lower till. of finely laminated 
blue clay free from 
Fig. 31. Fig. 32. 
Map AND SECTION OF CLay Point, ALron. Scale of map, pebbles, with its 
I inch=} mile. Contour lines are shown for each Io feet bottom nearly at 
above the lake. 
the level of the 
lake. It was underlaid by a stratum of coarse, water-worn gravel, con- 
taining iron-rust. This abrupt bank, which extends around the point 
fully a quarter of a mile, has resulted from the excavation of the clay 
by the waves of the lake. 
Near East Alton, two miles south-east from this point, a bed of 
gravelly and somewhat stony clay, at least seven feet in thickness, is 
overlaid by two or three feet of till at a height of about 200 feet above 
the lake. A mile anda half west from this place, clay of good quality, 
finely laminated and free from pebbles, occurs on the north and north- 
west side of a hill, at a height of 150 feet above the lake. Both these 
