528 Surface Geology of the Merrimack Valley. [September, 
on one or both sides into wide sandy “ pine plains,” so called 
because their principal wood-growth consists of white or pitch 
pines. These are often accompanied by a thick and tangled 
undergrowth of scrub oaks, which, with the pitch pines, flourish 
best on these barren plains. The terraces have a very level 
surface, with a regular but slight slope, which amounts to nearly 
the same as the descent of the river. 
At Franklin the upper terrace is well defined upon both sides 
of the valley. It has here considerable fall in a short distance, 
being four hundred and forty-five and four hundred and forty feet 
above the sea at the north side of Webster Brook and Winni- 
piseogee River, and descending in less than a mile to four hundred 
and thirty and four hundred and twenty at their south side. In 
the next nine miles the upper terrace falls to a height one hundred 
and twenty-five feet above the river, which continues for more 
than twenty miles to the north part of Manchester, the highest 
terrace seeming to descend most rapidly near the present falls of 
the river, so that a nearly uniform height above the river is 
maintained. 
In Canterbury the upper terrace spreads out into plains which 
are at some places a mile wide. The Boston, Concord, and Mont- 
real railroad through this town is upon these high plains, while 
the Northern railroad in Boscawen and Concord lies on the low- 
est terrace, being embanked much of the way to raise it above 
the floods of spring. The plains of the south part of Canterbury, 
extending one mile into Concord, show an unusually rapid, con- 
tinuous slope, amounting to eighty feet in four miles, or from 
one hundred and thirty to only fifty feet above the river. The 
north end of this slope appears to be at the normal height, rep- 
resenting the level of the river at the time of deposition of these 
plains, while its south end is about seventy feet below this nor- 
mal line, which is here shown on the west side in the plains 
north and south of Fisherville. 
Boscawen village is built on the south end of a similarly slop- 
ing terrace, three miles long, in which distance it falls thirty 
feet, and we find thirty feet more fall of the same terrace in less 
than a mile along the village street. The whole of this terrace 
is below the normal height, showing a deficiency of fifteen feet 
at its beginning and of forty feet at the north end of Boscawen 
village. 
The supply of alluvium brought down by th 
e river at this 
point was not sufficient to fill the valley to its average depth. 
