FRANKLIN COUNTY. 631 
The other chief use of the formation is in the manufacture of quick- 
lime. A large business of this sort is carried on in connection with the 
quarries referred to above. A notable part of the limestone, viz., eight 
to ten feet below the Delaware beds, is better adapted to this use than to 
any other. Too light for building purposes, it would need to be removed 
at great expense in order to reach the valuable courses below, were it not 
that it can be used in the lime-kilns with the best results. The analyses 
already given show the character of the lime produced. As has been 
already remarked, these quarries furnish the purest carbonate of lime 
burned, in the large way, in Ohio. It can easily be made to average in 
the kilns ninety per cent. of this substance ; but the economy of throw- 
ing in the ‘“‘spalls,” or fragments of the building-stone, instead of leaving 
them out as waste, reduces the percentage somewhat. The lower courses, 
it will be remembered, have a larger proportion of magnesia in their 
composition. The character of the lime is changed, to some extent, by 
this element, but it is not safe to say that it is injured for all uses. The 
most approved plastering limes of Ohio to-day are those manufactured 
from the Upper Silurian formations, the Niagara and the water-lime, 
which are, chemically, double carbonates of magnesia lime, and of these, 
the Springfield lime may be taken as a representative. For paper fae- 
tories, for glass-works, for blast-furnaces, and perhaps for gas-works, 
the product is to be valued in proportion to its percentage of lime; but 
in the wider use of lime, as mortar, a high percentage of this substance 
is not necessary to insure a high quality. The truth is, that the dif- 
ferent kinds of limestone yield different kinds of lime, and use has 
much to do in the value set upon anyone. They require different modes 
of treatment. Each will fail when subjected to the mode of working 
which the other requires. 
The Columbus lime is a very hot, strong, white lime, that can be made 
to do the best work of its kind in every respect. To one important use, 
in addition to all others, to which it has been applied, it seems likely to 
be put, viz.,to use as furnace flux. The furnaces that are already built, 
or are in process of erection in the Hocking Valley, have, it is true 
layers of limestone in the hills which contain their ore and coal; but 
these layers are generally light, and it can scarcely prove TieHEAble to 
follow them into the hills under cover, when limestone of such quality 
can be so cheaply furnished from the oy quarries of Columbus and 
vicinity. 
Columbus lime, like almost every other lime of Ohio, is burned with 
wood. Numerous attempts have been made to substitute bituminous 
coal for wood, in its manufacture. Most of these attempts have proved 
