1846.] Mineral Resources of JYew York. 39. 



which they are located. Those sections of the State which are 

 most deficient in good materials for building are the eastern coun- 

 ties; still, even here quarries of shale and thin-bedded sandstone 

 might be opened, which are quite important and useful. To be- 

 gin, however, with the Potsdam sandstone, the lowest member of 

 the New York system. This occupies a large territory in Jeffer- 

 son, St. Lawrence, Franklin and Clinton counties, and small in- 

 sulated patches in Lewis, WaiTen, Saratoga and Washington 

 counties. It, however, furnishes one of the best and most dura- 

 ble stones for building which has ever been used, being perfectly 

 weather tight, as well as indestructible under all changes of 

 weather, either above or below the surface. It furnishes the 

 finest material for building, flagging, or any purpose for which 

 stone may be employed at Potsdam. Being in most cases a fire 

 stone, it is used for hearths of furnaces and the like, and being in 

 many instances a purely silicious rock, white and free from iron, 

 it may be, and has been employed in the manufacture of glass. 

 It is the best flagging stone in the northern counties. 



The next series of rocks which produce materials for construc- 

 tion are the Hudson river rocks, or Pulaski and Lorrain shales 

 and the sandstones which terminate the Champlain division of 

 the New York system. But it must be said that the shales and 

 sandstones are liable to injury from the weather, when exposed. 

 The most durable are layers of this group which are found in 

 Oneida and Oswego counties, where some fine quarries have been 

 opened which furnish even-grained and even-bedded layers, for 

 grindstones as well as blocks for building. The only rocks which 

 fiirnish roofing slates are those of the taconic sj^stem. Hoosic, in 

 Rensselaer county, is the place best known for this material, and 

 the experience of thirty years proves it as valuable and durable 

 as the Welsh slate. 



The next series of rocks which furnish flagging is the Clinton 

 group in the Ontario division. The strata suitable for this pur- 

 pose may be found from Utica to Rochester. The quarries near 

 the former place, though not of the best quality, are still important. 

 At Rochester, the building and flagging materials are found in the 



