444 GEOLOGY OF OHIO. 
facture of charcoal pig-iron is still a very important industry in Southern 
Ohio, it does not require much foresight to see that its importance is on 
the wane, and that ere long it must necessarily yield to the use of min- 
eral fuel. Such has been the history of all the great iron manufacturing 
regions of the world when coal was accessible. Thus England, which 
in 1788 had 24 charcoal furnaces out of a total of 77, in 1872 had less 
than 5 in a total of 950. In the United States, east of the Alleghenies, 
the use of charcoal as a blast-furnace fuel nas been or is being entirely 
superseded by mineral fuel, and such must be the result whenever the 
facilities of obtaining coal render its use possible. Considering, how- 
ever, the supply of timbered land which Ohio still possesses, and the 
high value of charcoal pig-iron, this industry will be of some importance 
for considerable time to come. By a system of care, and strict economy 
in the use of the wood, and the employment of the best and most 
approved modes of manufacture, its duration can be lengthened, though 
the final fate of the industry is certain. 
It may be safely stated, that at present (1883) digeninhe of this 
available timber land of the Southern Ohio iron manufacturing districts 
has been cleared. Many furnaces are compelled to obtain their fuel 
from such a distance that its transportation becomes a very serious item 
in the cost of the iron made. 
The Coal Area of Ohio. 
Although this subject has been very fully treated in the Geological 
Reports, still, considering the primary importance of the coals in the 
iron manufacture, and the fact that all the points of the industry must 
draw its supplies from this area, and be situated in close relation to it, 
or actually within its limits, a brief summary of the general limits and 
character of the Coal Measures in Ohio can hardly be amiss here. 
‘The line which bounds the Coal Measures in Ohio will include the - 
eastern third of the State, or an area somewhat more than 10,000 square 
miles. This boundary line enters the State from Pennsylvania in the 
southeastern corner of Trumbull county, and then runs southward to 
near Youngstown, and westward to Ravenna, with a long span extend- 
ing northward into Geauga county. From Ravenna the boundary 
passes near Akron, Summit county, and then pursuing a more southerly 
and sinuous course it runs near the east line of Knox county, passing 
near Newark, Logan, and finally crosses the Ohio into Kentucky, near 
