BUILDING AND ORNAMENTAL STONES. 455 



feet. Quito heavy beds occur in some of the quarries, and the joints 

 allow blocks of very large size to be obtained. Iu the western ledge 

 the quarries are iu a line some 1,000 feet long by 150 wide, and are 

 worked to an average depth of about 12 feet. The total thickness of 

 the layers in this region is from 4 to 20 feet, and the stripping from 6 to 

 17 feet in depth. In working the quarries but little capital is required 

 beyond the value of the necessary tools, they being commonly leased and 

 royalty paid at the rate of one-half cent per square foot of stone quar- 

 ried. The larger size of blocks have dimensions of about 15 by 8 feet, 

 though some 20 by 15 feet have been taken out. At the time of taking 

 the census iu 1880 there were upwards of one hundred and fifty quar- 

 ries within the bluestoue district as given above. All, however, agree 

 so closely with those of Quarry ville, that further description seems un- 

 necessary. 



The quarry district in the Medina sandstone extends from Brockport, 

 Monroe County, to Lockport, Niagara County. The stone is, as a rule, 

 moderately fine-grained in texture, hard, and of a gray or red color, the 

 red variety being most used for building purposes, while the gray is 

 used in street-paving. The red variety has a bright and pleasing ap- 

 pearance ; both red and gray are sometimes used together, with good 

 effect. Most of the stone buildings in Lockport and Buffalo are of the 

 Medina stone. The most important feature of the stone is, however, 

 its adaptability for street-paving, in place of the usual granite or trap 

 blocks. It is said that the sandstone blocks have the advantage of 

 not wearing smooth, as do the granites and traps, while at the same 

 time they are nearly, if not quite, as durable. 



The stratum of quarry rock is put at about 30 feet in thickness, the 

 different layers of which vary in thickness from 18 to 30 inches. 



Three miles south of the town of Potsdam, in Saint Lawrence County, 

 the Eaquette River cuts across the Potsdam formation, and quarries 

 are worked along the banks of the stream. The outcrops at this point 

 are some 2 miles in width from north to south. In the quarry the 

 strata dip to the south at an angle of about 45°, the beds increasing in 

 thickness somewhat from the top downward, until at a depth of 40 feet 

 they are some 2 or 3 feet in thickness. In color the stone is light-reddish 

 or reddish-brown, and though, when first quarried, soft enough to work 

 readily, becomes most intensely hard on seasoning. It is very highly 

 silicious and is, without doubt, one of the most durable of all our sand- 

 stones. Owing to its hardness it has been as yet but little used for 

 general building purposes. Columbia College, in New York City, is 

 one of the most important buildings yet constructed from it. At Fort 

 Ann, in the same county, the stone is much lighter in color and com- 

 posed of almost pure silica, there being an almost entire absence of iron 

 oxides in the cementing material. The stone is, as a consequence, ex- 

 tremely hard, but tough and durable. 



North Carolina. — The narrow belt of Triassic sandstone already men- 



