76 SURFACE GEOLOGY. 
river, the lowest being interval. West of Hill village an expanse three 
fourths of a mile long and a half mile wide is divided, by escarpments 15 
and 20 feet in height, into three distinct terraces, the highest of which is 
410 feet above the sea. A small terrace, 80 feet higher, is found on its 
west side. The highest terraces west of the river, well shown much of 
the way between Hill and Franklin, are from 40 to 60 feet below those 
on the east. This difference seems to be due to a deficiency in the 
amount of material supplied, the deposition being influenced by the cur- 
rent, and attaining its full height only on one side. 
Kames. A short gravel ridge, projecting five feet above the plain of 
which it forms the border, and containing pebbles six inches in diameter, 
was seen in the north part of Franklin, on the west side of the road at 
one mile south from Hill village. Another gravel ridge, about 20 rods 
long and 35 feet above the plain on the west edge of which it occurs, was 
seen in Sanbornton near the river, a mile and a quarter south-east from 
the last. Both these short ridges are of typical kame gravel; they lie 
nearly in the middle of the valley, and their heights are about the same, 
the northern being 385 and the southern 365 feet above the sea. It is 
not improbable that these are remnants of a formerly continuous kame. 
This coarse gravel was next observed at a railroad cut on Bristol 
Branch, one mile above Franklin depot; an excavation of it may be seen 
in Franklin village, just north of Webster brook, at the west side of the 
street; and it is again exposed in the same way a short distance south of 
the depot. It also forms a ridge, nearly covered by the fine alluvium of 
the upper terrace, on the east side of the river, one fourth of a mile above 
the bridge. Southward in this town kames were noted at two places on 
the west side. 
At Boscawen village portions of a well marked kame form the escarp- 
ment of the plain, which has about the same height, near the north end 
of the street and south from the road to the bridge. One mile farther 
south we find between the highway and the railroad a ridge several hun- 
dred feet long, the north part of which is composed of coarse water-worn 
gravel, while its southern portion seems to be unmodified till. 
The ancient highest flood-plain of the Merrimack from Franklin to 
Massachusetts line is everywhere well shown by the conspicuous upper 
terraces. Along much of the way these expand on one or both sides into 
