712 GEOLOGY OF OHIO. 
whole. For iron making the supply is abundant, and it is found in so 
many different horizons that it will be difficult to find property on which 
there is not a full supply. | 
On the west, where the ravines cut the base of the Coal. Measures, ne 
Maxville limestone is accessible, which, at Webb’s Station and Maxville, 
is eleven feet thick. | 
About one hundred and fifty feet below the Great Vein is the Blue 
limestone, sometimes cherty, but often of good quality, reaching a thick- 
ness of two and three feet. It is exposed at Shawnee, Straitsville, and in 
the valleys to the west and south. 
Associated with the Baird ore, on the horizon of Coal No. 5,is a limestone 
which in other parts of the State sometimes reaches a thickness of six 
and ten feet, but seems generally thin in this field. It will probably be 
found here in places worth quarrying. | 
At about forty and seventy feet above the Great Vein are limestones 
in places five feet thick, frequently ferruginous, and carrying valuable 
ores. That at seventy feet is the limestone used as a flux in the furnaces 
‘at Shawnee, and is rarely wanting in any part of the field. 
The Cambridge limestone is about one hundred and seventy feet above 
the Great Vein, from two to three feet thick, and of good quality. 
The Ames limestone, two hundred and seventy to two hundred and 
eighty feet above the Great Vein, is two to three feet thick, and in places 
in Trimble township, Athens county, is reported by Professor Weethee 
as fifteen feet thick. Both of these limestones are very persistent, and 
each will doubtless make a good flux. In the eastern part of Trimble 
the limestones of the Pittsburgh coal are regularly developed, and are of 
good quality. Besides these there is a black limestone three feet thick, 
seen near Ewing, thirty-seven feet above the Bayley’s Run coal, bowlders 
of which, fallen down from their proper horizon, are often seen through- 
out the wholeterritory. There is no doubt that the supply of limestone is 
ample for all the wants of the smelting furnaces. 
The following table shows the composition of the limestones which 
have been analyzed: 
No. 1, Shawnee limestone, by S. B. Newberry: 
MICA seek eee le Ce clk Sec Say aR ne I Cie ks eae cau enna 9.9% 
18) 0101. ee eS eh oke See Er rtnne Seth ci ET RUS cB oy Geb oe eee 31.19 
Magriesia c.\2 ee seen eae tia et eI eV Lg Ea reaps enatctatammiarc tere Lo 630) 
Alumina and protoxide of iron): 3.22 oho o) ok ee ere ee POCO 
Oxideof manganese yaseasees cee sisce seer eee eee eaaceaeeseiee ome 
Sulphur oe... cose Se ee eae ral ata aetrate elcre epee eiereteente tera eetetaieieys tetera) emmy U nce 
Phosphorus..62 00 4 \:o Qo aU 0 ey RRR An oa UM MRO A 3) eee 0.05 
Carbonic acide. ecds sue hele ail ees a hia a eer ess dh Lee aD 
VERE 8S 200 0000 0006 60 006 0056 66 Go 0060.00 186 DODD co So COADUO Sa GOOD GEMS ES oC00e | OLE 
