INSCRIPTION OF THE IRON ORES. 
73 
Comparison of average analyses of Iron Springs iron ores with ores of Lake Superior and 
Alabama. 
Iron 
Springs 
ores. 
Lake Su- 
perior 
ores." 
Alabama 
henia- 
tites.6 
I ron (metallic ) 
56 
7 
.200 
4 
1 
3 
.027 
. 057 
. I'.Mi 
59. 6 
7. 5 
.007 
1.3 
1.5 
4.0 
37 
Silica ? 
115.44 
.37 
16.2 
Alumina 
3. is 
Water, above 220° 
. 50 
Sulphur 
.1)19 
.07 
L2.24 
« Average cargo analyses for 1905. 
i> Birkinbine, John, The iron ores of Alabama (average analysis by Dr. William B. Phillips): Nine- 
teenth Ann. Rept. U. S. Geol. Survey, pt. (i, 1898, p. 62. 
It will bo noted that the Iron Springs ores are intermediate in 
composition between the two other great classes of ores. 
SIZE AND QUANTITY OF ORE DEPOSITS. 
The iron-ore deposits vary from mere stringers to those having 
an area of 1,670,000 square feet. The aggregate surface of all the 
ore deposits of the district is -5,430,000 square feet or 0.2 square miles. 
The aggregate tonnage of all grades of ore in the district, deter- 
mined by multiplying the known area by the best available infor- 
mation as to depth in pits, drill holes, and erosion sections is 40,000,000 
tons. The largest single deposit, figured on the same basis, has 
15,600,000 tons. It is altogether likely that the figures are much 
too small rather than too large, because the depths used in the cal- 
culation have been those actually observed, and observation has 
not yet gone to the bottom. Inferences concerning the extension 
of the ore beneath the present workings, based on the manner of 
origin of the ore, are discussed on pages 87-89. 
DEVELOPMENT. 
During the years 1874 to 1S76 a small furnace, with a daily capacity 
of 5 tons, was built and operated at Iron City, 5 miles southwest 
of Iron Mountain. The product was taken to the then prosperous 
silver mining camp at Pioche, Nov., and to Salt Lake, Utah. Later 
the old stack was torn down and a new one, projected to take its 
place, never rose higher than the foundation. The coal was derived 
from the Harmony Mountains, 5 miles to the southeast. The ore 
used in this furnace was taken out of the Duncan claim, one of the 
southernmost exposures of ore in the Pinto groups of claims, from 
shallow pits and short tunnels near the surface. 
From time to time since the discovery of the deposits, pit- and 
tunnels have 1 been sunk in the ore, principally to meet assessment 
