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No. 50.] 357 
ble, the same disturbance in its parts, and the same water worn ap- 
pearance, which elsewhere in western New-York is so characteristic of 
it ; whilst the sandstone is more or less horizontal. 
Quitting the primary and proceeding west, we find the land rises with 
considerable altitude towards the source of the tributaries of the Black 
river. These take their rise in the sandstone and shales of Pulaski, and 
descend to the river over the Frankfort and the Black slate, the Trenton 
and the Mohawk limestones ; each of the latter rocks forming a narrow 
terrace for its great length, and, as might be supposed, the waters de- 
scending from one elevation to another, give rise to numerous cascades, 
some of great height and beauty. 
The two sides of the Black river strongly contrast with each other, 
as to rocks, soil, vegetation and population. The surface of the east 
side, or primary division, consists, with few exceptions, of an almost 
unbroken range of forest, spread upon an uneven surface, the result of 
materials or masses first disturbed, and subsequently water worn ; no 
part of its surface in Lewis county presenting elevations of conse- 
quence, excepting near the southern part, where it joins to Oneida : 
there it forms low mountain ridges. The western side of the river, on 
the contrary, is well settled, and exhibits those steps or terraces com. 
mon to horizontal rocks or undisturbed mechanical deposits, presenting 
an almost unbroken outline, the lowest mass of which, the Mohawk 
limestone, rises and forms the west side of the river valley, either by 
the side or upon the primary, and presents a cliff or mural precipice, ex- 
tending through the county. 
In no part of the whole of the division east of Black river, could I 
find or hear of any rock but which formed a part of its mass, with the 
exception of the fucoidal layers and the Potsdam sandstone ; and these 
were partial, confined to narrow limits, and north of a line passing from 
the natural bridge to Harrisville. Thus it is obvious, that the county 
is naturally divided into two geological divisions, the eastern formed of 
primary masses, and the western those of the transition class. 
With this brief outline of the geology of Lewis county, we proceed 
to such observations as relate more particularly to an economical report. 
From all that I had time or opportunity to observe, the primary mass 
presents but few rocks, consisting chiefly of granite and that peculiar 
kind of gneiss common to the west primary region of New- York. This 
