630 GEOLOGY OF OHIO. 
well upon it. Much of it can be made to take a very good polish. An 
establishment for rubbing the stone has lately been set up in Columbus 
“and is doing good work. 
As to durability, which after all is the main element in determining 
its value as a building stone, it can be said that the Corniferous lime- 
stone furnishes much material decidedly above the average of limestones. 
The chief drawback les in its highly fossiliferous character. Some- 
times the fossil is so firmly cemented in the body of the rock that there 
is no more tendency to the weathering of the stone about it than else- 
where, but oftener, there is aslight difference in composition between the 
fossil and the rock, the fossil being the firmer. 
Along the line of union, atmospheric agencies take easy hold, and a 
few years are sufficient to give to the dressed block a rough and un- 
promising appearance. Examples enough can be found of this agency 
in the best building for which the limestone has yet been used, viz., the 
State Capitol. Thinner courses, those measuring six or eight inches, 
are generally the ones that show worse in this respect, and smoothly 
dressed surfaces are disfigured more than others. It is within the 
architect’s province to so use the stone as to escape the appéarance of 
weakness and decay, for the evil chiefly lies in the unsightly face which 
the slight weathering produces. The strength of the block when well 
laid is good for centuries. 
The thickness of the several courses of cutting stone may have been 
already noted. Almost any required thickness can be furnished within 
the limits of four and sixty inches. To make an enumeration, we find— 
A 4-inch course; a 6-inch course; a 7-inch course; an 8-inch course; a 
10-inch course; an 11-inch course; a 12-inch course; a 14-inch course; a 
16-inch course; a 19-inch course; a 24-inch course; a 27-inch course; a 
30. inch course; a 34-inch course ; a 60-inch course. 
One other important use to which this limestone is put, is in the 
making of road-beds. Like other limestones, this one proves unsatis- 
factory for the surface of a much-used roadway. It grinds quite easily 
into fine dust, the lightness of which allows it to be lifted into the air 
very easily. But when used as a foundation for concrete or other surface, 
it serves a very useful purpose. 
The principal quarries now worked, are the two of which sections 
have been given, viz., the State quarries, and Smith and Price’s quar- 
ries. The former are taken to include the many openings that are made 
in the immediate vicinity of the quarries owned by the State, as well as 
these extensive excavations. Numerous parties are now engaged in 
quarrying, in a small way, on both sides of the river, for four miles. 
above the city. 
