228 MICA SLATE. TALCOSE SLATE. 



belt of it runs north and south nearly through the 

 centre of the state, striking north into New-Hamp- 

 shire and Maine. It forms Saddle Mountain in 

 Williamstown, near 4000 feet high, and the highest 

 point in the state. The Taconic range, extending 

 through Berkshire county, and south through Con- 

 necticut and Dutchess county, is composed of mica 

 slate, and so also is a great portion of the Hoosack 

 Mountain range, which includes ail the elevated land 

 between the valleys of Berkshire and the Connecti- 

 cut. It often approximates to argillaceous and tal- 

 cose slate in Berkshire county, and is sometimes 

 mistaken for them. The mica slate formations in 

 New-England generally run north and south, and 

 the strata, for the most part, dip to the east, with an 

 angle of from 20 to 90 degrees. This rock is ex- 

 tensively used for flagging the sidewaks of cities, as 

 it is easily split into layers. 



Talcose Slate. — This is another of the primary 

 rocks, and under it may be included chlorite slate 

 and steatite, or soapstone, as these are only varie- 

 ties of the same species. It is composed of talc 

 and quartz, though it sometimes contains other in- 

 gredients, as feldspar and hornblende. We find it 

 connected with mica slate in New-England, as in 

 the Hoosack and Green Mountain range, and very 

 perfect specimens of it may be observed in Hawley 

 and Plainfield. It also abounds in the Middle and 

 Southern States. Steaite or soapstone abounds 

 in the vicinity of the Rocky Mountains, where it is 

 procured by the Indians for the bowls of tobacco- 

 pipes ; also near the Falls of St. Anthony ; in Mary- 

 land, near Baltimore ; in Pennsylvania, near Phila- 

 delphia ; and Staten Island, where it forms a large 

 proportion of the elevated grounds on the eastern 

 part of the island. It is extensively employed for 

 aqueducts, coal furnaces, &c. 



Granular Limestone. — There is no rock more ex- 

 tensively diffused than this, and none more readily 



