Scudder. } 3 8 0 [November 19, 
recent production of tidal currents. If the passage has ever been — 
open and afterwards closed by the action of the sea, the same process 
would probably follow with an artificial breach, or at least the cutting 
could be kept open only at a great and constant expense. 
The beach between the sea and the harbor at this point is nowhere 
more than two or three metres above high water, and to all appear- 
ance is wholly composed of dune sands. ‘There are, however, some 
important indications that it is as old as the island itself. With slight 
differences, consisting mainly of the greater or less amount of clay 
commingled with the gravel, the structure of the eastern bluff of 
Nantucket is essentially the same from Siasconset on the south to 
Haulover Beach on the north. It is interrupted once at Sachacha 
Pond, where the sea occasionally sweeps across into the lake, but 
there are broken patches of the old bluff still remaining, and no one 
could believe that the material underlying the low beach at Sachacha 
was not so old as that underlying the bluffs near at hand. ‘The bluff 
to the north of Haulover beach, although at its southern end formed 
only of blown sand, is further on identical in structure with that to 
the south of the beach; so also is that which skirts the head of the 
harbor on the northern side, where it is full of boulders of consider- 
able size, showing that the whole Coskata district to the north was 
formerly part and parcel of the original island. 
In this case, one point of connection of the two now separated 
bluffs must have been at Haulover beach. Although, without further 
testimony, it appears the more probable, it does not follow, that the 
present beach is a remnant of the old; since the beach may have beer 
entirely destroyed, and then, by the changed action of the sea, in- 
duced by some altered relations of currents, been reconstructed. 
There is, however, one feature in the beach itself which seems to pre- 
clude the latter supposition ; for, near its northern limit, but still far 
from the gravelly cliffs beyond, may be seen a single small thin patch 
of stratified clays underlain by layers of compacted ferruginous 
gravels, such as could not have been formed upon a beach at or 
above tide water, and essentially resembling similar patches in the 
bluff further southward. The patch is doubtless the last remnant of 
the cliff formerly existing here, but which has been torn down by the 
sea upon one side and the harbor upon the other. The Haulover 
beach is therefore but a repetition upon a larger scale of the Sachacha 
beach to the south. 
