fornia, and in Oregon.—5. Franklinite. This
is an ore analogous in composition to magnetite,
but part of the iron is replaced by
manganese and zinc. Its formula is (Fe, Mn,
Zn)O, (Fe, Mn)₂O₂. It crystallizes in the
isometric system; specific gravity about 5; hardness
5.5 to 6.5; streak dark reddish brown.
It contains about 46 per cent. of iron, 17 of
manganese, and 13.5 of zinc. It occurs at
Franklin furnace and Stirling Hill, N. J. It
is first treated to extract the zinc, and the residues
are then smelted for spiegeleisen.—The
reductibility of iron ores depends more on their
molecular structure than their chemical
composition. While the natural magnetites are classed
with the more refractory ores, owing to their
dense structure, the magnetic oxide resulting
from the roasting of spathic ore is reduced
with ease. The same contrast is noticed
between the anhydrous and hydrous hematites.
CONSTITUENTS.
HEMATITES.
HYDROUS HEMATITES.
CARBONATES.
MAGNETITES.
SPATHIC ORE.
EARTHY CARBONATES.
BLACKSAND.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
Ferrous oxide
. . . .
2.34
1.670
. . . .
. . . .
. . . .
. . . .
46.22
4.69
43.84
46.43
35.14
39.92
45.27
37.07
41.45
7.704
27.55
23.56
. . . .
. . . .
. . . .
Ferric oxide
90.55
91.45
90.87
70.380
76.87
47.49
81.55
. . . .
67.22
0.81
. . . .
7.62
3.60
0.64
. . . .
. . . .
54.715
58.93
52.44
. . . .
. . . .
. . . .
Magnetic oxide
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
94.25
94.20
79.78
Manganous oxide
0.10
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
10.55
. . . .
12.64
1.44
0.50
0.95
. . . .
0.23
. . . .
. . . .
0.10
10.40
. . . .
. . . .
. . . .
Manganic oxide
. . . .
. . . .
. . . .
4.005
. . . .
4.32
0.10
. . . .
3.36
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
0.934
. . . .
. . . .
. . . .
. . . .
0.28
Silica
7.05
3.99
5.18
9.185
0.71
26.70
4.53
1.08
12.49
. . . .
10.29
21.91
8.76
11.24
2.70
3.02
20.532
12.54
3.10
4.32
5.10
0.75
Alumina
1.43
1.40
0.89
1.232
. . . .
7.34
1.49
. . . .
2.49
. . . .
4.80
2.67
7.86
8.14
. . . .
1.33
4.034
0.29
2.05
0.28
. . . .
4.62
Lime
0.71
0.51
1.76
0.880
. . . .
1.67
trace
0.75
1.25
0.28
0.76
3.64
7.44
1.72
6.61
. . . .
4.643
0.38
1.20
0.14
. . . .
0.13
Magnesia
0.06
0.22
0.13
0.211
. . . .
0.25
0.47
2.73
4.11
3.63
0.94
0.08
3.82
1.51
7.40
0.89
2.222
0.61
1.05
. . . .
. . . .
2.04
Alkalies
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
0.24
0.27
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
Water (ignition)
. . . .
. . . .
. . . .
13.797
19.25
8.90
11.70
0.09
. . . .
. . . .
1.38
2.05
2.97
0.03
. . . .
0.18
1.418
0.11
. . . .
0.38
. . . .
. . . .
Organic matter
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
1.14
. . . .
. . . .
0.95
9.80
23.58
2.941
. . . .
. . . .
. . . .
. . . .
. . . .
Carbonic acid
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
38.38
3.35
38.86
30.44
24.05
22.85
30.32
36.14
28.06
0.760
0.12
6.10
. . . .
. . . .
. . . .
Phosphoric acid
trace
0.141
0.069
0.310
0.10
2.67
0.16
. . . .
trace
. . . .
0.74
trace
1.86
0.17
0.23
not det.
0.719
trace
0.009
0.87
0.50
. . . .
Sulphuric acid
. . . .
. . . .
. . . .
. . . .
3.10
. . . .
. . . .
. . . .
0.49
. . . .
trace
0.42
. . . .
. . . .
. . . .
0.006
0.498
. . . .
. . . .
Titanic acid.
12.08
Sulphur
0.03
. . . .
0.078
trace
. . . .
0.24
. . . .
. . . .
. . . .
. . . .
0.04
. . . .
0.11
trace
. . . .
0.040
FeS₂
0.143
0.04
. . . .
Chromic oxide with
trace of vanadium.
0.32
99.93
100.051
100.647
100.000
100.03
99.58
100.00
99.80
99.45
100.06
98.40
98.32
100.41
99.99
100.18
98.556
101.263
100.67
99.909
100.24
99.80
100.00
—The
distribution of the iron ores of the United
States, with relation to the resources of the
country in mineral fuel, has been well stated
in the “Report on Iron and Steel” of Mr.
Abram S. Hewitt, United States commissioner
to the Paris exposition of 1867, as follows:
“The position of the coal measures of the United
States suggests the idea of a gigantic bowl
filled with treasure, the outer rim of which
skirts along the Atlantic to the gulf of Mexico,
and thence returning by the plains which lie
at the eastern base of the Rocky mountains,
passes by the great lakes to the place of beginning,
on the borders of Pennsylvania and New
York. The rim of this basin is filled with
exhaustless stores of iron ore of every variety,
and of the best quality. In seeking the natural
channels of water communication, whether on
the north, east, south, or west, the coal must
cut this metalliferous rim, and in turn the iron
ores may be carried back to the coal, to be
used in conjunction with the carboniferous
ores, which are quite as abundant in the United
States as they are in England, but hitherto
have been left unwrought, in consequence of
the cheaper rate of procuring the richer ores
from the rim of the basin. Along the Atlantic
slope, in the highland range from the borders
of the Hudson river to the state of Georgia, a
distance of 1,000 miles, is found the great
magnetic range, traversing seven entire states in
its length and course. Parallel with this, in
the great limestone valley, which lies along the
margin of the coal field, are the brown
hematites, in such quantities at some points,
especially in Virginia, Tennessee, and Alabama, as
fairly to stagger the imagination. And finally,
in the coal basin is a stratum of fossiliferous
ore, beginning in a comparatively thin seam in
the state of New York, and terminating in the
state of Alabama, in a bed of 15 feet in thickness,
over which the horseman may ride for
more than 100 miles. Beneath this bed, but
still above water level, are to be found the coal
seams, exposed upon mountain sides, whose
flanks are covered with magnificent timber,
