PENNSYLVANIA. 



105 



145. Here is the deepest of all oil wells, hut unproductive. 



146. The valley of the Alleghany River is full of derricks from here to Oil City; and the valley 

 of Oil Creek up to Titusville. 



147. Lubricating oil from the first oil sand. 



148. Numerous gas wells used for lighting the city, heating, rolling iron, &c. 



149. Commencement of the importance of the Sharon bed as a "block coal" raw fuel for iron 

 furnaces. It becomes the great bed of Ohio. 



150. Old iron making centre. Banks of the river faced with terraces of ferriferous limestone 

 supporting large deposits of Hmonite (" buhr stone") iron ore, of the lower productive coal series. 



