SUPPLEMENTAL REPORT—HOCKING VALLEY. 905 
10. The ore next to be named is, beyond all question, the most valu- 
able of the Ohio series. It lies at the very center of what has been our 
largest and most successful iron manufacture therto. It is the chief 
element in the geological scale of a large section, all limestones, coals, 
and other ores being located as so much above or below this horizon. It 
is known in the southern counties as the limestone ore, and the use made 
of this designation suggests the importance of the seam. It is called the 
limestone ore because it generally rests directly upon a well known lime- 
stone, viz, the Gray or Hanging Rock Limestone; but there are two 
other ores, at least, that have an equal right to this name—being aaso- 
ciated in the same way with limestones—yet both are ignored in common 
use, and this name is applied to the seam now under consideration, 
without uncertainty or ambiguity. The name, however, is in some ways 
a misleading one; it suggests composition rather than situation, but 
with the former it has nothing to do. Some lime enters into this seam 
as into so many others, but the proportion is not nearly as large as in 
other Ohio ores. Another designation is commonly given to this seam 
in Hocking and Perry counties. It is here known as the Baird ore. At 
Union Furnace, Hocking county, it is styled the red ore. The identity of 
these several ores has been fully established, and will be demonstrated 
in a subsequent part of this report. 
Like the ores of the Coal Measures, the limestone ore is a carbonate or 
siderite under heavy cover and a hydrated sesquioxide or limonite on its 
outcrop. The varieties are known as gray or blue limestone ore and red 
limestone ore, respectively. 
The gray variety is one of the best marked ores in Ohio, and is uniform 
in character through all the district which we are considering. Samples 
from Lawrence, Gallia, Scioto, Jackson, Vinton, Hocking, and Perry 
counties cannot be distinguished from each other. Metallurgical suites 
from the Hanging Rock Furnaces were collected during the progress of 
the survey, and specimens of the gray ore came in the sets of the follow- 
ing furnaces, viz. : 
ILO Clase > enue mere es Sirneeiata kil ei Ie AN Sence SOO SHU So eee Lawrence county. 
DUCES WTS Oh Re an ak A pa nee Te CS: AE ge oe 
WORST ANTM EE Sy aU Ca A a ea a aE ie 
ASTROS eB SA BEM SOAS SOIT TIC RIEU SER CIES EINE Jel an BN Een Bean fe us 
DADA WLR ENESCO SS och ei: GEA TOMES eae ee eat SE SR a ef PY 
(ORS TALBESP SAS SNS ek Eytan Upscale rat ANU Oo AI Nl a a ae fs es 
IMIESAVORT OMY, Sore oe eet aes ey RMN Nee Raney ah Baal ita kai a gs ‘¢ 
LEUNG) AVON ETAL RCP PIR cies a IRS Fic icy tks aes coi om Os Ne PERT Gis ye 
COUN AE) enc: et aR RE RUS epee art OT pO Oe a eg ON Mt OG 
