No. 200.] 
369 
layers is often very beautiful . The stone is a very pure siliceous sand- 
stone, separating into laminas or layers of from one eighth of an inch 
to eight inches thick, with very even surfaces. The position of this 
stratum, or bed, has already been noticed as occurring in the midst of 
the red marls. 
The limestone, particularly in the lower strata, furnishes a superior stone 
for building. Only at intervals, however, even the same strata furnish 
a similar material, for at one point we may obtain regular blocks of al- 
most any required dimensions, and often at a short distance the same 
stratum is divided into thin laminas. The best material of this kind 
in the county, and indeed, far the best I have seen in the district, is ob- 
tained at the Cold Spring quarries near Lockport. At three points with- 
in a mile of each other, and within three miles of Lockport, this stone 
is obtained. Two of the quarries belong to Mr. W. D. Shuler and the 
other to Messrs. Skinner & Day. The stone is of a light gray colour, 
generally compact, or sub-crystalline, though often exhibiting a porous 
surface. They are among the most durable materials for construction, 
as may be proved by examining the locks on the canal at Lockport, 
where the same kind of stone has been exposed to all changes of tem- 
perature, and to freezing water, still the stone remains firm. The ce- 
ment with which these stones were laid, has been removed by the action 
of water and ice long since, and consequently the stones have been left 
with only their own specific gravity to hold them in their places. Not- 
withstanding all this, the locks are in better condition than any others I 
have observed in the western part of New- York. "Wherever this stone 
has been used in buildings, it remains unchanged by the action of at- 
mospheric agents. It is extensively used at Buffalo, Lockport, Roches- 
ter, and many of the villages along the canal. The quarries are favora- 
bly situated, being on the brow of the mountain ridge. The descent is 
rapid entirely to the canal, half a mile distant. 
As a prejudice exists with regard to this stone, it may be proper to 
give some explanations. The stone is said to crack if exposed to frost 
immediately after being quarried, and from this it is inferred that the- 
same would be the result if exposed to freezing water. It is known 
that all rocks contain moisture, as is perceived on breaking a stone re- 
cently removed from the quarry; this moisture evaporates on exposure. 
In rocks of a crystalline structure, as in the present instance, the pro- 
portion of this moisture is greater than in those which are compact and 
not crystalline. Its presence renders the stone brittle on first exposure, 
but after its evaporation it becomes tough. Gun flint is exceedingly 
[Asscm. No. 200.j 43 
