266 
[Assembly 
On the top of the hill to the right, going to Clockville, are the 
plaster beds" of Mr. Brown, about a mile and a quarter from Clock- 
ville. The quarries present a range of detached masses more or less 
round upon the top, but generally smaller and with a flat surface below 
The whole of the gypsum is enclosed in the usual thin layers of dark 
brownish, and apparently a much altered rock. Above the gypsum 
are a few of those which immediately overlie it, exhibiting the hopper 
shaped cavities, and the porous or " vermicular" rock, but all in no 
great quantity, some of the plaster masses being at no great depth be- 
low the soil. 
The plaster hills range from east to west through the county, extend- 
ing south of the turnpike for above three miles. The hills are more or 
less round, rendering some portions of their plaster accessible, the 
layers in which the masses exist having but a slight inclination. 
In Onondaga there are some appearances of working for plaster at 
the north ends of the hills at Hartsville, and L. H. Roach works a 
plaster bed in the village. He remarked that there were as many as three 
courses of plaster. I saw no hoppers or porous rock in his quarry, but 
there were fragments amongst the rubbish around. 
Further west on the turnpike towards Syracuse, are the quarries of 
Groves and Everson. Besides these quarries in Manlius, are those of 
Balsley, Potter and King. 
In the town of De Witt we have the quarries of Dunlap, Brewster, 
Wilcox, Burks, Dr. Smith, Edwards, Hurd, Reals, Rumley, and of Hun- 
gerford. This latter exhibits the best gypsum that I saw in Onondaga. 
It belongs, I should judge, to the upper range; it has no porous rock, 
and was followed about 12 feet above by the terminal mass of the 
group. This quarry presents a fine arching over the gypsum, the ele- 
vation being considerable, and the arch unbroken. This elevation of 
the layers is an unerring guide in the search for gypsum ; it exists in no 
part of the range without a plaster mass being under it. Hungerford's 
quarry is about a mile or two below Jamesville, on the road to Orville. 
After leaving the town of De Witt, there are few plaster beds that 
are opened to the west in Onondaga. The greatest quantity that is regu- 
larly quarried is by the rail-road that goes to Split rock. The next that 
I saw was that of Mr. Hunt's to the southwest of Syracuse, near On- 
ondaga valley. 
