32 S. W. Ford—Primordial Rocks of Troy, N. Y. 
Art. VIL.—WNotes on the Primordial Rocks = the vicinity of Troy, . 
N. Y.; by S. W. For 4 
In view of the prevailing uncertainty respecting the age of 
the rocks of that portion of the Taconic series of Professor | 
Emmons lying east of the Hudson river, I was led several years | 
ago to undertake the investigation of some of these rocks in my 
own neighborhood, though I had but few hopes of learning any- 
thing essentially new about them. It soon became apparent 
that much valuable information might be obtained from them; 
and from certain facts which early came under my observation — 
I was induced to continue their study. I propose here to. 
notice briefly some of the more noteworthy results thus far’ 
on te 
evidently eastward, and at a high angle. They extend eastward 
about half a mile, and form a hill of cokes forkcshe magnitude - 
within the city limits. Following the course of this hill north- 
ward, we find them frequently well exposed in railway cuttings, 7 
and before reaching Lansingburgh, which is — miles ci | 
in a bold elevation several hundred feet i in hei - 
noutherty, aid a pear to be all construe 
upon nuke same pattern, having on the west a steep, on the east 
a more gradual slope. lag. the western ges are naturally 
exposed. This uniformity of structure is very striking, 
there are reasons for believing that it has sented largely 
successive short, sharp folds in the — of which we have @ 
—— -east of Lansingburgh; but as near! 
