176 IJ-H. Winckell on a great 'Pri'/nordial Quartzyte. 
as if thev were made yesterday. ' F"ig. 12 [not re-produced] is a transverse 
section of one of the valleys described above. The walls on either side 
are rounded and scratched. Their depth varies from 10 to 100 feet. 
The sandstone of Potsdam hears a land transportation of from 15 to 20 
miles; and at these distances from the quarries it is considered as cheap 
a material for building as brick, and I venture to say there is no stone in 
the state, or anywhere else, equal to it for durability. As regards beauty 
individuals may differ, but there is no stone superior to it in this respect, 
unless it is marble. All the sandstones and freestones which are brought 
to the New York and Albany markets, crumble more or less, and suffer 
eventually from the weather, but this will resist attacks of all the natural 
agents to which it may be exposed. * * * As afirestone the Potsdam 
sandstone is held in the highest repute. Composed as it is of siliceous 
grains, compacted together by compression, it is calculated to resist the 
highest degree of heat; and as it is uncrystallized it is not liable to crack 
by this exposure. All the furnaces of St. Lawrence and Jefferson counties 
have their hearths of this sandstone. Another use to which I conceive 
this stone may be applied, is for grinding hard bodies, and perhaps it mav 
answer for coarse grindstones, and for some particular offices where a 
certain degree of hardness is required it may be superior to the ordinary 
stones. 
From this place this formation strikes across the St. Lawrence 
river toward the northwest, and is represented as far west as 
Bedford in the county of Frontcnac, on the geological map 
of Canada, 1863. 
Thence westward it is lost, and the country is represented as 
occupied by the Laurentian. A formation of its persistency of 
character and thickens however can hardly be expected to dis- 
appear so soon, and it is the purpose of this paper to call atten- 
tion to the great probability that the great primordial quartzyte 
of Minnesota and Wisconsin is the same as that described by 
Dr. Emmons at Potsdam. 
In the first place all the physical characters that are men- 
tioned by Dr. Emmons, and those that are given bv Prof. Hitch- 
cock in the Vermont reports, as belonging to and characterizing' 
the "sandstone of Potsdam," are perfectly applicable to the 
quartzyte seen at Pipestone, ^Minnesota, and the same in Bar- 
ron county, Wisconsin. One might take the description of Dr. 
Emmons in his hand, and, standing on the qtiartzyte ranges of 
' Dr. Emmons is here evidently describing the well known glacial 
stria:; which are ever_\- wlicre beautifully preserved on tliis rock through- 
out the Northwest. 
