DRIFT DIVISION. 
171 
At and about Wading river, blocks and boulders are found in the greatest profusion. One 
block that had been blasted in pieces for walls, gave one hundred cart loads, and many others 
were seen still larger. One block of gneiss at Wading river was a singular one, and may be 
considered as adding another fact in the chain of evidence, tending to show that gneiss is but 
an altered sedimentary rock, formed as the sandstones have been, and as beds of sand now 
are. A sketch to illustrate the lamination may be seen in Plate 36, fig. 4. 
On the beach a little west of East brook, or a little more than a mile from Wading river, a 
block of fine-grained limestone containing serpentine was found. It was precisely similar to 
the New-Haven verd-antique marble. Greenstone boulders and blocks were not rare in the 
same vicinity; and at two miles west of East brook, a block of trap was seen on the beach, 
that contained at least one hundred cubic yards. 
Between Miller place and Old Man’s, the surface is pebbly, with blocks and boulders of 
gneiss and granite. Near Old Man’s, the hills are steep, and elevated about one hundred 
to one hundred and twenty feet above tide water, with a light loamy soil. On the lower level, 
pebbles and blocks are numerous. Many blocks of one hundred tons or more each were seen; 
and in one place half a mile east of Old Man’s, is a nest of five or six of these enormous 
blocks, which, but for their lines of bearing and dip varying very much in the different blocks, 
would almost lead one to suppose that a similar rock was in place just beneath the surface. 
One block of gneiss on the road leading to a house at the head of a small cove, three-eighths 
of a mile east of Old Man’s, was smoothed on one side, and was also scratched like the dilu¬ 
vial grooves and scratches often seen on rocks in place. The part on which this smoothed 
and scratched surface was exposed, had been recently uncovered of earth. The part that 
had been above ground, was weathered and rough. 
Only a few boulders of greenstone, and a single one of red sandstone, were observed in 
travelling from Miller’s place to Smithtown. 
Fragments of a block of porphyritic granite were observed near Setauket, similar to that in 
the vicinity of Reading, and of Sterling and Killingly in Connecticut. It had been blasted, 
and made into a wall. 
In Smithtown, about half way between the village and Stony brook, a boulder of about two 
tons weight was observed, composed of a coarse siliceous conglomerate with a siliceous cement. 
It resembled some of the coarse conglomerated coal grits of the coal region of Pennsylvania, 
the conglomerate grits of some of the peaks of the Catskill mountains, of the Shawangunk 
mountains, and some of those about Boston (Mass.) and Newport (R. I.). There were no 
distinctive characters by which I could refer it to its parent source. The pebbles in it were 
from the size of hazlenuts, to a six pound shot. 
Some boulders were seen on Mount Pleasant, but they were not abundant. This swell of 
ground is elevated about one hundred feet above the Smithtown valley, and in the whole of 
that valley a single boulder was not observed. 
In Huntington, at Dix hills, four miles west of Commac, the same character of hills is 
observed as at the Shinnecock and Montauk hills, namely, they are small, round-backed, 
