18 Bulletin of the New York State Museum. 



FOREST OF DEAN MINE, Monroe, Orange County. — The 

 Forest of Dean mine is five miles west of Fort Montgomery on the 

 Hudson. It is opened on a large ore-body or "shoot," which pitches 

 north-east at an angle of 27°. The walls dip steeply south-east. The 

 slope is 1,350 feet long and descends on the bottom rock at the angle 

 of 27°. A "horse" of rock divides the ore at the roof, the rock of 

 which, unlike that of the walls, indicates the synclinal fold structure. 

 The ore is medium fine-crystalline and rather friable, inclining to a 

 shot-like structure. Calcite, red and white, occurs in it, in scatter- 

 ing, crystalline masses. It is a rich, non-Bessemer ore. An analysis, 

 communicated by A. Tower, of Poughkeepsie, shows: 



Silica 5.00 per cent. 



Alumina _ Traces 



Lime _ 5.51 



Magnesia . _ . _ 1.19 



Oxide of Manganese _ 63 



Oxides of Iron. _ 83.56 



Phosphoric Acid _ _ 2.30 



Carbonic Acid 1.05 



Water 20 



The ore is sold to furnaces on the Hudson river and in the Lehigh 

 Valley, Pennsylvania. The mine water is raised in a vertical shaft, 

 which is located 900 feet north-east of the slope ; and there are two 

 (10-inch and 8-inch) 5 feet drawing-lift, and one 12-inch plunger 

 pumps. The hoisting and pumping are done by means of water power. 

 There are two overshot water wheels 40x6 feet. One air compressor 

 supplies compressed air to the power drills. The ore is run direct from 

 the mine on a tramway, three miles to the dump, where it is transferred 

 to wagons and thence carted two miles to Fort Montgomery. It is 

 shipped over the West Shore railroad and by boats. 



The Forest of Dean is one of the oldest mines in the State and 

 was worked, as reported by Dr. Beck, 21 years previous to 1777. It 

 is the property of the Forest of Dean Iron Ore Company, of Pough- 

 keepsie. Its output since 1865 is reported to be 430,756 tons. 



DUNDERBERG- OR HERBERT MINE, Stony Point, Eock- 

 land County. — An iron mine was opened many years ago on the 

 north side of Dunderberg mountain, one and a half miles west of 

 Iona Island. The ore is said to be lean and to contain pyrite. No 

 work has been done recently. 



