4 TRAVELS THROUGH 



Crayn I faw them cloathed by birch, beech, ancf 

 chefnut trees, a few excepted, which were cloathed 

 by firs. 



They confift more or lefs of horizontal and large 

 beds or ftrata ; and they are truly fuper incumbent 

 mountains, fet in all thefe parts upon a foundation 

 of fchiftus or flate, which constantly runs under 

 ground. This fchiftus is either a true clay- flate, 

 of a blue or black colour, or a horn-flate, com- 

 pofed of quartz and glimmer, how and then offer- 

 ing fome clayifh mixture. 



I had almoft at every ftep an opportunity of 

 being convinced that this fchiftus conftantly ran 

 under the vifible lime-ftone hills. Sometimes it 

 rifes bare above ground, and continues fo for fome 

 diftance -, but foon after it is hid again under its 

 calcareous covering. The lead- mines in Steyer- 

 marck, and the mercury-mines at Hydria, are funk 

 into this fchiftus, through the fuperior lime-ftone- 

 ftrata. I fee by fome accounts and foflils from 

 Tyrol, which you have communicated to me, that 

 this adjacent country is of the fame conftrudtion ; 

 and though the ore in the Steyrifh iron-mines near 

 Eifenaerzt is found in limeftone, there is no doubc 

 but fchiftus would be found in a greater depth. 

 I (hall give you a particular account of thofe places 

 in Auftria, Steyer, and Crayn, in which I obferved 

 that quality of thefe hills and other objects worth 



your attention. 



At 



