PKANKLIJSI COUNTY. 611 



The description now given applies to the stratum, as shown in the 

 quarry, under discussion. The stratum extends through the formation, 

 wherever shown in Franklin county, but it is only in a limited area, 

 even in this quarry, that it presents all of these points of interest. Else- 

 where scarcely a single square foot can be found which does not contain 

 some fragment of a tooth or plate ; but here these elements make up the 

 substance of the bed. Several chemical analyses have been made up of 

 this layer. Two, executed at the Ohio Agricultural and Mechanical Col- 

 lege, by Mr. C. C. Howard, gave the following results : 



No.l. 



Triple phosphate of lime 16.80 



Carbonate of lime 73.24 



Carbonate of magnesia 4.97 



Oxide of iron 2.46 



SUicions matter 2.14 



99.61 

 No. 2. 



Triple phosphate of lime 18.32 



These specimens are exceptionally rich in phosphate of lime, and can 

 not be taken to represent fairly the composition of the whole bed to 

 which they belong. 



An analysis is reported to have been made by Prof. H. B. Cornwall, of 

 Princeton, New Jersey, which indicated as much as five per cent, of phos- 

 phate of lime for the body of the rock. If continuous deposits should 

 hereafter be discovered, that would average as well as many samples now 

 found, they could be turned to economical advantage for fertilizers. 



The bone bed can be traced from the State quarries, the southernmost 

 point at which its horizon is exposed, to the north line of the county, 

 / being easily recognizable in every section in which its presence is due. 



The identification of most of these exposures was first made by Mr. W. 

 Farrar, a student of geology in the Ohio Agricultural and Mechanical 

 College. 



The discussion of its origin and history will be reserved for a subse- 

 quent page in the report. 



It will be remembered that the bone bed makes the boundary between 

 the Delaware and the Columbus divisions of the Corniferous limestone. 

 Immediately above it, in Smith and Price's quarries, three feet of very 

 thin bedded, shaly limestones are found. The same formation can be 

 traced along the water-courses that descend to the river here, until 

 twenty feet, at least, is added to the quarry section. The Delaware beds 

 here have but little in common with the same division on the northern 



