CHAPTER LXXXIX. 
SUPPLEMENTAL REPORT ON THE GEOLOGY OF THE 
HANGING ROCK DISTRICT. 
BY EDWARD ORTON, ASSISTANT GEOLOGIST. 
A heavy sandstone covers Coal No. 6 through a considerable part 
of its outcrop in Ohio. In Lawrence county this rock is well developed, 
especially in those portions that border on the Ohio River. Near the 
village of Hanging Rock it shows itself in very bold and picturesque 
escarpments, from which the village derives its name. 
The manufacture of pig iron in Southern Ohio was begun on Brush 
Creek, in Adams county, but the supply of ore found there, derived from 
Upper Silurian limestones, proved limited and uncertain, and it was not 
long until the seat of the manufacture was transferred to the western 
border of the Coal Measures in Scioto and Lawrence counties. A very 
prosperous and important industry was soon developed here. Several of 
the earliest furnaces were located near Hanging Rock, and their iron 
was distributed from that point as a center by means of river transpor- 
tation. The products of these furnaces was thus known as far back as 
fifty years ago as the “ Hanging Rock Iron.” The name was naturally 
extended so as to include all the iron made from the general geological 
horizons that were worked by these earliest furnaces. These horizons 
were gradually followed back from the river through county after county, as. 
far as the Hocking Valley, the old Logan Furnace being the last one 
whose iron was counted Hanging Rock Iron. 
The belt of country thus occupied is about sixty-five miles long and 
from ten to twenty miles in breadth, its longer axis bearing about 
twenty degrees west of south. Upon it fifty furnaces have been estab- 
blished, and the best of the iron made in them has become the standard of 
comparison throughout a large portion of the Mississippi Valley. For 
some important uses, indeed, there is good reason to believe that no 
better iron has ever been manufactured in the country. 
The ore seams that have been worked in the Hanging Rock district 
are very numerous, but one seam enjoys such easy and undisputed 
