Secondly, a '' rock four chains and sixty links north of the brook," (the first stream above the Sing Sing brook,) " fixed by Bedford committee to begin to measure up the river."^

Mining operations were formerly carried on to a considerable extent in Sing Sing, under the flattering idea that silver ore existed here ; the old shafts sunk for this object are still visible. The following entries in the Secretary of State's office, refer to these mines. No. 54.] Stephen Lyon, Westchester county, town of Mt.

Pleasant, about 100 rods south of

the discoverers dock, and about 80

rods south of the farmers dock

at Sing Sing landing, upon lands

of John F. Marsh, (gold and silver.) Nov. 14, 1820. 41. 204. No. 57.] Stephen Lyon, Westchester County, town of Mt. Pleasant,

additional vein south of the mine,

which is now on file, extending 1 mile

south of said mine, (gold and silver.) Jan. 30, 1824. 41. 296. Galena has teen obtained here in small specimens, as well as several ores of copper ; one specimen of the latter yielding from 50 to 75 per cent, also iron pyrites, Sulphuret of zinc and oxide of manganese occasionally occur in the lime stone rock. "Sing Sing is also celebrated for its marble quarries, which are worked to a great extent by the state prison convicts, who have here erected two large prisons, a keeper's house and several ranges of work -shops from materials found on the state farm." The mar-