564 
GEOLOGY OF THE FIRST DISTRICT. 
It has been opened in several places along the crest of the mountain to a depth from three to 
twelve feet. The ore is disseminated in the gneiss and granitic rock, through a thickness of 
five to twenty feet. The strata are nearly vertical. It is on one of the crests of the eastern 
ridge of the Highlands, west of Peekskill hollow, 
A slight opening has been made about three-fourths^ of a mile north-northeast of the Gou- 
verneur mine, between that and the Coalgrove mine. The ore is titaniferous, and in lumps 
and disseminated in the rock. The vein is six to twelve feet wide. It may perhaps be 
worked by picking the ore, so as to separate the lumps from the gangue. 
The mines and openings just described are the principal ones on the Phillips veiu,. but the 
ore can be found along almost the whole line. It follows the crest of the east ridge of the 
Highlands a distance of at least eight miles. The breadth of this vein has been mentioned 
at different places from three to thirty feet wide; its average is probably about twelve feet, 
and its length, as now known, about fourteen thousand yards. If the mean average of the 
vein be supposed to be half its bulk of ore, every cubic yard will contain about two tons of 
ore, and would yield at least one ton of iron, or each yard in depth would make fifty-six 
thousand tons of iron. The vein, by proper working, can be mined to a mean depth of one 
hundred yards, without expense of drainage, more than the proper opening of adits. We 
may place the workable produce of this vein above the water level of the adjacent valleys, 
at 5,600,000 tons of iron. 
The phenomena of the mines in many places on this vein induce the idea of igneous injec¬ 
tion,. connected with a powerful upheaving force. The felspar is often pearly, wrinkled, and 
with bent laminEe.. The appearance of hyalite, a mineral usually associated with volcanic 
and trap rocksthe apparent injection in veins among the seams and crevices of the rock; 
the appearance of the softening of the gneiss and bending its layers like a flowing slag, seem 
to point to an. igneous origin of this vein. It often has the appearance of a bed, and at other 
times of a vein ramifying from a main mass between the strata, and at other times cutting 
obliquely across them, but still having its outcrop parallel to the line of bearing. 
The Coldspring furnace is the only blast furnace ia operation in the counties of New-York, 
Westchester and Putnam. It is supplied with magnetic oxide-of iron from the Phillips mine, 
the Denny mine in Putnam county, and from the Townsend mine in Canterbury, and the 
O’Neil mine in Warwick, Orange county. These ores are mixed in certain proportions, and 
flux each other easily with a small addition of the Singsing limestone. The produce of this 
furnace is from one thousand to fourteen hundred tons of pig iron per annum. 
Bonnell’s forge in Phillipstown is believed to be the only one in operation in the counties- 
under consideration. It is supplied with the shot ore of the Stewart mine. 
