Geology of the Catskills. 249 
of Colonel Straton, it would appear that the polish thus giv- 
en to granite, may be said to be as imperishable, as the ma- 
terial itself to which it is applied. 
1 had an opportunity of making these observations while 
engaged in erecting a granite monument, ornamented with 
black pilasters. - The workmen succeeded most perfectly in 
giving the black polish to the granite, in the manner I have 
described.” 
Art. [1f.—Notice of the Geology of the Catskilis ; by 
Mr. D. W. Barton, of Virginia—uwith a Plan. 
Tux study of Geology becomes more satisfactory, the 
nearer approach to perfect uniformity, we discover in the ar- 
rangement and stratification of the same minerals in different 
parts of the world—when they exhibit the same internal 
structure—the same relation, position, and the same asso- 
ciation with other minerals. It is an object of noless impor- 
tance to be able to establish the geological identity of remote 
sections of the same country, and to trace particular mine- 
rals through an extent of several hundred miles, with little or 
no interruption of continuity, and invariably accompanied 
by the same rocks. I have recently examined, with some 
degree of minuteness, the geology of the Catskills and their 
vicinity, with a design to compare the northern extremity 
of the transition region of the U. States with acorresponding 
section in the south. The result of my observations is ex- 
_ hibited in the accompanying chart. If in some instances I 
have not given to a stratum of rocks its appropriate designa- 
tion, the error will be of little consequence, since it cannot 
materially affect the accuracy of the comparison which I 
propose: 
In addition to this imperfect delineation of the geology of 
the Catskill Mountains, I am enabled to notice several lo- 
calities of minerals which have not hitherto been described. 
Ist, On the side of the Mountain which rises immediately to 
’ the north of Kaaterskill clove, and about a quarter of a mile 
from the dwelling of Mr. Absalom Smith, is a ledge of com- 
mon argillaceous slate, from which during the winter and 
spring, issues a smal] stream, strongly impregnated with 
alum. On arriving at the surface of the rock, the fluid is 
