1846.] Mineral Resources of JYew York. 41 



the bottom and sides, and the sixth, with its perforation, the top, 

 completes the structure. 



Flagging stone possessing properties of the same kind as those 

 just described occur also in the Catskill sandstones above. Near 

 the Mountain House a quarry of very fine stone has been opened. 

 We have spoken of this rock as it occurs near the Hudson, and of 

 its existence at points from whence it may be transported to mar- 

 ket. It extends, however, from the Helderberg to Lake Erie, and 

 from the Hamilton group to the top of the Catskill, as we have 

 already stated. Hence numerous quarries may yet be opened in 

 the westward prolongation of this series of rocks, and every vil- 

 lage, almost, may be provided with fine and beautiful walks, as 

 well as building material, when the layers are of a proper thick- 

 ness. In New York the value of a material of this kind is imper- 

 fectly understood. In England, stone, however coarse, is reckon- 

 ed as a part of the estate as much as the soil. 



The limestones of New York are more circumscribed than the 

 flag stones; but still, many localities furnish important and valu- 

 able stone for construction. The lowest or oldest deposits belong 

 to the taconic system. The gray and white marbles of Westches- 

 ter at Sing-Sinn; are the most noted. These marbles are not all 

 equally good. The dolomitic are friable, and w^aste and break 

 when exposed to the weather. Sulphuret of iron often stains and 

 spoils large blocks, and segregated masses of silex often injures 

 them for polishing. Passing up to the New York system, we 

 find that the lowest limestone, the calciferous sandstone, is a valu- 

 able rock, and when blocks are well dressed it is an excellent ma- 

 terial for building, for locks and piers. It resists the weather, 

 damp or dry, warm or frosty. The best locks of the Erie and 

 Champlain cnnals are constructed of the calciferous sandstone. 



The next limestone w^hich may, or which has been used for 

 construction is the birdseye. It is a pure carbonate of lime, and 

 ages of exposure to the weather are required to make a percepti- 

 ble impression upon it. It is used in Oneida and Lewis counties 

 for the construction of dwelling-houses. The Trenton limestone 

 is black and gray, the latter variety is used for building; the 



