THE IRON ORES. 435 
of all the main ore belts. Something must be found from which to 
make a stock pile, and the Oak Ridge “ore” answered for this purpose, 
and it also served to use up the charcoal supply of Oak Ridge Furnace 
during its first and only blast. The ore lies about 20 feet above the 
Cambridge limestone. It isa lean and coarse deposit, kown in but a 
small territory and not likely ever to be mined again as a source of 
pig-iron. 
This completes the review of the main horizons at which iron ore 
is or has been mined in the State. Several of these horizons have been 
found to be strictly continuous, and but few of them are limited in their 
extent to a single locality. Even those ores that are most restricted, 
generally come in at the horizons of other vital elements in the series, 
as coals and limestones, and thus the anomaly of their occurrence, to a 
certain extent, disappears. 
The composition and adaptation to furnace use of these several ores 
have been treated only incidentally in the present chapter. These sub- 
jects will be more fully discussed in the following chapter, where also 
the general conditions of iron manufacture in Ohio will be considered. 
