BUILDING STONE. 621 
stone is strong and durable, and none of it has as yet shown any bad 
effects from exposure to moisture or frost. It is rather hard to dress, 
and stone-workers call it ‘“‘ plucky.” The horizontal surfaces are gene- 
rally roughened by small angular prominences which fit into corres- 
ponding depressions in the superimposed layer, forming the structure 
which is known as “ suture” jointings. The dip here is very slight, and 
the top course in allof the Findlay quarries is evenly bedded and about 
1 foot thick. The “seams” (open joints) are from 25 to 100 feet apart, 
and the close joints usually run at right angles to these seams at greater or 
less intervals. For this reason, if the quarry is stripped over a sufficient 
space, the rock can be obtained without blasting. The material from 
these quarries is used for the foundations of buildings and for bridge 
abutments in the county, and last year some was shipped to Seneca and 
Allen counties. 
In composition the stone from the Findlay quarries is dolomitic 
and possesses the characters of the upper Niagara beds. In microscopic 
structure it is beautifully crystalline, the whole mass of the rock being 
made up of an aggregate of more or less well-defined rhombohedral 
crystals. 
It appears that blocks much larger than can possibly be required are 
obtainable here, and that the material, although at present used only for 
rough construction, could be safely applied asa building stone. Although 
the present quarries have been opened quite recently, along the same 
streams upon which these are situated and within a short distance of 
them, quarries have been in operation for more than twenty years. 
LowER HELDERBERG.—The Lower Helderberg formation is ex- 
posed in a narrow strip (a) upon the boundaries of Highland and Ross 
counties, and indeed more stone is taken from the quarries at Greenfield 
than from any others in the Helderberg formation of Ohio. The stoneis 
regular in its bedding, and, therefore, curbings and crossings of excellent 
quality are easily extracted. In the Cincinnati market it is largely 
employed for these purposes. Slabs 3 or 4 inches thick, with a super- 
ficial area of 4 feet, can be obtained with surfaces as smooth and regular 
as if sawed. ‘These stones can be used for door-steps and like purposes 
without any dressing. ‘The courses are never heavy, seldom exceeding 
14 inches, and usually ranging between 4 and 8 inches in thickness, 
(a) Geological Survey of Ohio, Report of Progress in 1870, p. 255: “ Geology of Highland County,’’ 
by Professor Edward Orton. 
