LlMONITE OF STATEN ISLAND. 61 



HILLSDALE OR SMITH MINE, Hillsdale, Columbia Co.— 

 The Hillsdale and Smith mine is in the limestone valley, about three 

 miles east of Hillsdale village and near the Massachusetts line. It was 

 opened in 1834 and has been worked at intervals, the last time in the 



summer of 3 887 by Northridge, of Brooklyn. Geo. W. Palmer 



of 132 Nassau st., New York, is the owner. The ore has to be carted 

 to Hillsdale station on the N. Y. and Harlem railroad. 



MITCHELL MINE, Hillsdale, Columbia County. — This mine 

 is on the farm of A. & W. Mitchell, three miles north-east of Hills- 

 dale village. It has been idle for twelve or more years. It was first 

 opened in 1800. 



HAIG-HT OR FOSTER MINE, North Hillsdale, Columbia 

 County. — The opening on the estate of Edward Haight, deceased, 

 at North Hillsdale, bears this name. The location is in the valley, near 

 the slate on the west, and a quarter of a mile west of the valley 

 road. It was opened first in 1862, and was worked a little, five or 

 six years ago by a New York city company. The nearest railway 

 line is at Hillsdale. 



VI- THE LlMONITE, OR BROWN HEMATITE OF STATEN 

 ISLAND (RICHMOND COUNTY). 



NEW DORP MINE, TOWLE MINE, COOPER & HEWITT 

 MINE, Middletown ; TYSON'S MINE, Castleton. 



The above-named mines are the larger openings in the brown 

 hematite deposits of Staten Island. They are all in the north-eastern 

 part of the island and on the range of serpentine rocks. The geologi- 

 cal occurrence has been described briefly by Mather,* and recently 

 by Dr. N. L. Britton, of Columbia College, f According to the 

 latter authority the ore rests directly upon the serpentine or talcose 

 rocks and is generally covered by the glacial drift. It ranges up to 

 twelve feet in thickness. The lateral extent is limited to a few 

 hundred feet in any direction. The ore varies in the percentage of 

 metallic iron from 38 to 55 per cent, according to published analyses. J 

 It contains a notable amount of chromium. Dr. Britton has 



* Natural History of New York : Geology of the first Geological District, by Wm. 

 W. Mather, pp. 489-490. 

 t Annate of the New York Academy of Sciences, Vol. II, pp. 175-177. 

 t Tenth Census of the United States, Vol. XV., pp. 122-127. 



