232 
[Assembly 
forms a stratum which is generally about two feet in thickness, and can 
be split out in slabs of from 10 to 100 square feet, and from one to four 
inches thick. The rock is traversed by joints that divide the slabs 
about perpendicular to their layers, and smooth as if cut by a saw. 
There are two, sometimes three sets of these joints which divide the 
rock into regular blocks, and facilitate the labors of the quarrymen. 
Similar joints traverse the whole rock series under examination, (viz : 
the Catskill mountain group.) These joints are remarkable for their 
smoothness, and are nearly uniform in their directions. 
The stratum of flag stone is from 700 to 1,000 feet above the Hel- 
derberg limestone series. It is quarried in Sullivan county for the sup- 
ply of that and Orange counties ; but the principal quarries are in Ul- 
ster, Greene and Albany counties. It has been estimated that fifty 
loads per day pass through Kingston to the landing for five months in 
the year, for shipment to New-York and other places, which would give 
about 900,000 feet as the amount shipped from Kingston. Saugerties, 
Coxsackie, Bristol and New-Baltimore, send in the aggregate about 
2,500,000 feet more. The aggregate amount of flagging stone quarried 
in Sullivan, Ulster, Greene and Albany counties, may be supposed to 
be about 3,500,000 feet per annum. 
The principal quarries near Kingston, are owned by Judge Hasbrouck, 
who leases them to the quarrymen for $5 per M feet, and as each 
square yaid will give on an average from 50 to 70 feet, each acre may 
be conceived to yield 300,000 feet, and thus give the proprietor a clear 
income of $1,500 per acre, from land which was purchased a few years 
since for one dollar per acre. 
This rock ranges from the Delaware river, through Sullivan and Ul- 
ster counties, nearly parallel to the Delaware and Hudson canal, to 
within 4 or 5 miles of Kingston ; thence nearly parallel to the Hudson 
to opposite Saugerties ; thence around the Catskills to the mountains 
east of Rensselaerville ; and thence westward through Schoharie coun- 
ty, a distance of about 140 miles, without reckoning the winding line 
of outcrop, in consequence of various irregularities of the ground. 
The flag stone rock, like many others of this series that do not disin- 
tegrate by exposure to the weather, frequently forms terraces, and in 
many places it is but slightly covered by soil, or by a thin stratum of 
rock which is similar to this, except that it does not split as regularly. 
The quarrymen select such places as present the least obstruction to 
