SHELBY COUNTY. 459 



seat, near the end of the bridge over the river, as before stated, is near 

 sixty feet below the canal, these figures would give to the Clinton a 

 rise in level with horizon of about thirty feet in that distance. 



The surface of bedded rock underlying the Drift in Shelby county is 

 doubtless worn unevenly, in some places rising above the level indicated 

 by the top rock, on the Miami, below Sidney, in others sinking more or 

 less below that level — perhaps, in places, greatly below. 



Rising sometimes to one hundred and sixty-four feet, maintained gen- 

 erally at a level ranging from figures but a little lower than this, down 

 to seventy-five feet (seldom going lowrir), we may conclude that there is 

 an average depth of Drift in the county of one hundred feet. This depth 

 of Drift is not equaled in any of the counties wliich lie south of this. 

 We are here on the line which bounds the deep Drift on the south. 



The opportunities to ascertain the nature of the Drift are numerous in 

 the excavations made in constructing the canal and railroads, especially 

 the Indianapolis and Bellefontaine branch of the Cleveland, Columbus, 

 Cincinnati and Indianapolis Railnad, which runs at a considerably 

 lower level than the Dayton and Michigan road, which runs through the 

 county in a north and south direction. At the point where the east and 

 west road runs below the track of the Dayton and Michigan, on the 

 western border of Sidney, a good opportunity ia afforded of seeing the 

 nature of the Drift for a distance of thirty or forty feet below the surface. 

 About one mile east of the bridge over the river, on this road, is a still 

 deeper cut. There is little stratification observed in the deposit as seen 

 through these deep cuts. Sand and gravel largely predominate in the 

 composition of the Drift as seen here, mixed with clay and numerous 

 granitic or quartz bowlders, varying in size from mere pebbles to masses 

 containing from ten to twenty cubic feet. The gravel, sand, and bowl- 

 ders are distributed through the clay, and all are lying in confusion. It 

 seems to me safe to say that fully twenty-five feet in thickness of clear 

 gravel, were it separated from the clay, would be found in the Drift 

 throughout this county— a quantity so inconceivably great that I will 

 not undertake to express it in figures, more than to say that it would 

 yield twenty-five million cubic yards to the square mile. But this gravel 

 is too much commingled with clay to make it available, in general, for 

 ballasting or road-making, and with all this the county is not abundantly 

 supplied with good gravel for such uses, well distributed in different 

 localities. Enough has, however, been found to construct a system of 

 free turnpikes not surpassed, in extent or excellence, by those of any 

 county of similar size and situation in the State, although the material 

 has had to be hauled, in some instances, for inconvenient distances. I 



