No. 276. J 
stone lies in high knobs, and can be easily opened on the northeast side^ 
and Prof. Cassels thinks good marble may here be obtained. This lo- 
cality is about two miles west of Whitlock village, through which it 
is supposed the New- York and Albany rail-road will pass. 
Limestone was seen by Prof. Cassels on Plumb creek, about a mile 
west of Somerstown plains, on the Peekskill road. It occurs along the 
road for about half a mile. 
Limestone occurs about two miles north of Phittlockville. It is also 
said to occur on Mr. Todd's farm, about a mile east of the locality 
above, where it has been used for making lime. Prof. Cassels saw it 
again about three-fourths of a mile south of the crossing of Titicus 
river. It is here abundant, and fine quarries might be opened. It 
crops out on the road side occasionally all the way to North Salem, 
where it is abundant and highly crystalline. A stratum of limestone 
was seen by Prof. Cassells about a mile north of Owenville, and again 
about a mile and a half west of Peach pond. 
A marble quarry is opened nearly opposite Harlaem, in Westchester 
township, one-fourth of a mile north of Harlaem bridge. It is gray 
and white, and more or less mixed with mica. It is quarried for the 
piers of the rail-road bridge. The strike is north 25° to 30° east, and 
dip 80° WNW. It is associated with gneiss, with which it was seen 
in contact on the east side. 
A bed of dolomiiic limestone occurs near the county poor-house of 
Westchester county. It is called sandstone by the people, because it 
crumbles to sand by exposure to the weather. The same bed was seen 
at intervals to Dobbs' ferry. It crosses the valley of a small stream 
near the church on the hill at Dobbs' ferry. It forms the shore below 
Dobbs' ferry. A quarry is opened in this bed one-eighth of a mile from 
the shore of the Hudson, a mile below Dobbs' ferry, and a rail-road and 
wharf have been constructed to facilitate the transport and embarkation 
of the marble. Lime has been burnt from this stone on the shore, and 
some of the rock has been transported to New- York and burnt. 
The Sing-Sing marble quarries are extensively wrought by the con- 
victs of the State prison. Almost all of the limestone of these quar- 
ries crumbles by exposure to wet and frost, though it frequently requires 
many years to disintegrate. Near the surface the rock is perfect dolo- 
mite, covered by calcareous sand from the crumbling of the rock. 
At a greater depth the rock is sound, hard and tough. The bluish 
