ONTARIO COUNTY. 
455 
The course of the Canandaigua outlet, from Manchester village to near Vienna, is along 
the line of the Saliferous group and Water-lime, leaving the latter entirely on the south, and 
the former, with the exception of a few beds, on the north. East of Vienna, all the marl and 
gypsum has been removed, and is replaced by a deep deposit of sandy alluvium. In the west 
of Manchester, the same thickness is observed; and on the north side of the outlet, instead 
of the gypsum, we find alluvial hills rising eighty or one hundred feet above the valley, but 
not appearing south of the stream. From Manchester to the west line of the county, a low 
valley extends along the southern boundary of the gypseous rocks, with alluvial bills rising 
on its northern side. The original course of the Canandaigua outlet appears to have been 
north ; and it is very evident from the character of the rocks along which it passes, after 
turning east, that this portion at least was excavated recently, or long after the, deposition of 
the alluvium, which may have closed its northern egress. 
The principal quarries of gypsum are those of Robinson, Norton & Co., Cook, Vander- 
mark & Co., and Hildreth. From these about six thousand tons annually are ground at the 
mills on the outlet, and sold within the county. The supply is sufficient for a much greater 
amount, and unless the demand increases, the quarries will not be exhausted in many years. 
Whenever this happens, explorations will extend north of the present quarries ; and in all the 
valleys along the north part of the county, the middle series of plaster beds will probably be 
found. 
The water-limes are better developed in this county than in Seneca, appearing in their 
characteristic drab color. The mass may be traced almost uninterruptedly from near Oak’s 
corners, in Phelps, to Manchester village ; and beyond this it appears at many points, as on 
Mud creek, and near Victor village. East of Vienna, all the strata of this division are highly 
calcareous, and burned only for common quicklime. The principal quarries and kilns are 
within one and a half miles of the village. It is also quarried for buildings and enclosureSj 
the layers being sufficiently thick. It becomes stained with iron on exposure, and in almost 
every locality it is highly bituminous. 
At West-Vienna, this rock is burned for hydraulic cement, and is-said to produce a very 
good quality. Two miles farther west, at the quarry of Mr. Maffit, large quantities have been 
used for this purpose. At this place, the stone varies little in external characters from that 
used for lime. It consists of three distinct varieties : two only are used for the cement, while 
the lower course is composed of thin layers of tough argillaceous, bluish limestone, breaking 
on exposure into small irregular fragments ; and in mineral character, it is precisely the same 
as the strata which pass through the gypsum beds on the north side of the Canandaigua out¬ 
let. This portion, on burning, melts into a coarse porous slag, externally glazed and yellowish. 
The second stratum consists of thin layers, externally drab-colored, siliceous in texture, and 
harsh to the touch. This is succeeded by a few layers of irregular thickness, lighter in color 
than those below, and much more calcareous. Of the two last mentioned, each at intervals 
partly takes the place of the other, so that their thickness is variable, and the dividing line 
takes an undulatory direction. The whole depth of the two masses together varies from 
three to seven feet. If the lower of these is burned alone, the cement will not “ set ” under 
