xt74b853fp9q https://exploreuk.uky.edu/dips/xt74b853fp9q/data/mets.xml Moore, Philip North, b. 1849. 1876 books b96-12-34875167 English Printed for the Survey by J.P. Morgan & Co., : [Frankfort, Ky. : Contact the Special Collections Research Center for information regarding rights and use of this collection. Iron industry and trade Kentucky. Iron manufacture of the Kentucky Division of the Hanging Rock Iron Region / by P.N. Moore. text Iron manufacture of the Kentucky Division of the Hanging Rock Iron Region / by P.N. Moore. 1876 2002 true xt74b853fp9q section xt74b853fp9q

GEOLOGICAL SURVEY OF KENTUCKY.
N. S. SHALER, DIRECTOR.

THE IRON MANUFACTURE
,lF rTlF KENTUCKY DIVISION OF THE

HANGING ROCK IRON REGION,

BY P. N. MOORE.

PART V. VOL. I. SECOND SERIES.

317 & 318

This page in the original text is blank.

SOME NOTES UPON THE IRON MANUFACTURE
IN THE KENTUCKY DIVISION OF THE
HANGING ROCK IRON DISTRICT.

The Hanging Rock Iron District takes its name from a
peculiarly shaped rock exposure upon the Ohio river, near
which is now the village of the same name. Some of the
early furnaces were located near and had here their landing
place. The name Hanging Rock pig iron was applied to the
product of these furnaces, and as the number of furnaces
increased the name was still retained, until now it is applied
to all the iron produced in a number of adjoining counties, in
both Ohio and Kentucky. The region now embraces in Ohio
the whole or parts of Scioto, Lawrence, Gallia, Jackson, Vin-
ton, and Hocking counties, and in Kentucky, the counties of
Greenup, Boyd, and Carter, and it will, without doubt, eventu-
ally extend still further to the southward.
In this region the native ores of the coal measures are those
in most general use. They are used exclusively by the char-
coal, and very largely by the stone-coal, furnaces.
The Hanging Rock iron has an excellent reputation through-
out the West. It is used for a variety of purposes; but perhaps
more generally for foundry purposes than any other. For gen-
eral foundry use, combining strength with fluidity and small
shrinkage in cooling, it is probably unsurpassed in this country,
if anywhere. It can also be used with a considerable propor-
tion of scrap without injury to the resulting castings.
Certain brands of the cold blast charcoal iron have a national
reputation for the manufacture of car-wheels, for which purpose
they are unsurpassed.
The iron from the stone-coal furnaces of this region is used
for both foundry and mill purposes, but most largely in the
mills, for conversion into wrought iron. The fuel in use at a
majority of the furnaces is charcoal. It was upon charcoal iron
319

TIlE IRON MANUFACTURE OF THE

that the reputation of this region was established. It was not
until within the past ten years that the use of stone-coal for
the manufacture of iron was introduced. It has grown rapidly
since that time, and is destined to become the prevailing indus.
try; but as yet the charcoal largely outnumber the stone-coal
furnaces. There are in this region sixty-one furnaces, either
in active operation or in a condition to be put in operation in
a short time. Of the whole number, forty-four are charcoal
and seventeen stone-coal. Of these, thirteen are situated in
Kentucky, of which eleven are charcoal and two stone-coal
furnaces.
The following is a list of these furnaces:

CHARCOAL FURNACES.

Name. When County. Owners.
built.

Bellefont 1826 Boyd . . Means, Russell & Means.
Bo-ne . . . 1856 Greenup . Nathaniel Sands & Co.
Buena Vista. 1847 Boyd . . Means & Co.
Bufflo - . . 1851 Greenup . Culbertson, Earheart & Co.
Hunnewvell 1845 Greenup . Eastern Kentucky Railway Company.
Iron Hills I 1873 Carter . . Iron Hills Railway, Mining,.and Manufacturing Company.
Laurel 8. 849 Greenup - Robert Scott & Co.
Kenton . ... Greenup . Kenton Furnace Railway and Manufacturing Company.
Mt. Savage . 1848 Carter . . Lexington and Carter County Mining Company.
Pennsylvania. 1845 Greenup . Eastern Kentucky Railway Comprany.
Raccoon . t833 Greenup . Raccoon Mining and Manufacturing Company.

STONE-COAL FURNACES.

Ashland.. . 869 Boyd . . Lexington and Big Sandy Railroad Company, East'n Div.
Norton. . 1873 Boyd . . Norton Iron Works Company.

In addition to these, there were quite a number of furnaces
formerly in operation in this region, which have been discon-
tinued from various causes, usually either poor original loca-
tion, exhaustion of timber supply for charcoal, or unsuccessful
management. They were all charcoal furnaces, although one
of them, Star Furnace, used stone-coal during the last few
years it was in operation.
320

HANGING ROCK IRON REGION.

The following is a list of these:

Name. IWhen built. County. Builders.

Argillite .1.8... . 1822 Greenup Timble Brothers & Deering.
Pactolus. 1822 Carter MclMurtril & Ward.
steamn... . .. 1824 ,reenup. Shreve Brothers.
Enterprise .... . 1826 Greenup . Deering, McCoy, Clingman & Co.
Amandla ...... . 1829 Greenup Pogue Brothers, Culvert & McDowell.
Clinton. 1830 Boyd. Pogue Brothers.
6lOb.1830 Greenup Darlington & MlcGee.
Hopeweti..... . 1833 G;reenup Wm. Ward.
Caroline.1.3. 3 reenup.. Henry Blake & Co.
oikland... .. . 1834 Boyd .. . .. Kouns Brothers,.
New lampshire . 1846 Greenup .
Star. . . . 1848 Carter.
Sndy. .. . .. . 1853 Boyd.

The most of the above given dates and names of builders
were kindly furnished the Survey for publication by Col. J.
Iell, of Ashland. Mlr. J. Russell, of Bellefont Furnace, also
furnished information which aided the completion of the list.
From the above list it will be seen that the first furnaces of
this region were Argillite and Pactolus, built in 182 2. It has
been stated by 'Mr. Andrews, in the Ohio Geological Report
for 1870, page 217, that the first furnace in the Hanging Rock
region was the Union Furnace, built in i826, by Sparks, Means
& Fair. From the above list it will be seen that three Ken-
tucky furnaces in this region were built before Union Fur-
nace, viz: Argillite, Pactolus, and Steam, while two others,
Blellefont and Enterprise, were built the same year. To
Kentucky, then, properly belongs the credit of having first
started the manufacture of iron in this now important region.
Although not relating immediately to this region, the fact is
worth stating at this place, that in Kentucky was built the first
iron furnace in the WVest, and one of the earliest in the coun-
try. This was called Slate Furnace, and was situated in Bath
Coullty, upon Slate Creek, a branch of Licking river. It was
built as early as I791, and went out of blast after about thirty
wears operation. Of the Hanging Rock furnaces given in the
above list, Argillite, Hopewell, Pactolus, Enterprise, and Globe
were built adjacent to water-power, which was used for driving
'a t. 1-21 321

THE IRON MANUFACTURE OF THE

the blowing machinery. Argillite, Hopewell, and Pactolus
were upon Little Sandy river, Globe and Enterprise upon
Tygert Creek. The water-power was not sufficient at all
times of the year, and in one case at least a furnace was
chilled by the failure of the water requisite to drive her blast
engines. The result was that they were all soon abandoned.
and others erected using steam-power. The first furnaces
were of small size compared with those of the present time,
and their production was correspondingly small. Steam Fur-
nace, for instance, was first erected twenty-eight feet high by
eight and a half feet bosh, and is said to have produced only
three tons of iron per day. It is reported that Argillite Fur-
nace was still smaller, being only twenty-five feet high by six
feet bosh, and made only two tons per day. The site for this
furnace was excavated out of the shale near the end of the
dam, and it was so low that in time of floods the water could
only be kept from the furnace by means of coffer-dams.
The present charcoal furnaces are much larger, and produce
from ten to sixteen and even twenty tons per day. They are
nearly all built after the old model, with a massive stone stack
in the form of a truncated pyramid. With one exception, Iron
Hills Furnace, the model of all the charcoal furnaces, is the
same. They are built against a hillside, at the base of which
the rock is excavated to give room to place the stack. The
ore and charcoal are hauled in wagons to the stock bank at the
level of the furnace throat, and thus the necessity for an ele-
vator is obviated. The boilers are placed over the furnace
throat. and the hot blast ovens at the end of the boilers, so
that the waste gases are utilized effectually. The engine in
common use is horizontal, with one steam cylinder working
two blast cylinders, which are geared in such a manner that
when the piston of one is at its least velocity the other is at
its greatest, and thus a comparatively constant pressure of
blast is obtained without the use of a reservoir to regulate
it. The engines are usually geared to make one stroke of
each blast cylinder to two of the steam cylinder, which is
equivalent to stroke for stroke, as there are two of the blast
322

HANGING ROCK IRON REGION. 7

cylinders. The furnaces are usually worked with open hearth,
and most of them use but one tuyere, entering at the side.
The hearths are generally constructed of sandstone, of which
there is an abundance of good quality on most of the furnace
estates. Formerly the inwall or lining was also generally of
sandstone, but of late years the use of fire-brick for that pur-
pose has become more common.
Most of the furnaces are without either pressure gauge or
pyrometer, so that the pressure and temperature of the blast
are not known with any accuracy, the general rule being to
heat the blast as high as possible with the ovens at command,
and to keep the pressure as great as the steam will allow,
varying it, of course, according to the necessities of the furnace
working. It is probable that the general pressure of blast
does not vary much from two and a half to three pounds.
The following table gives the principal dimensions and other
details of the charcoal furnaces in this portion of Kentucky:
323

THE IRON MANUFACTURE OF THE

Ioo t o tt :,- X
..o. - a. .
..,' ) N-_N -NN NC4 . 0

'000je4os a- +;;o-aOo

- VI 0,0 ,+0 - .0

I-

_ ___. . -.
'0 0VX 04. 0 _)Nl -

_o _ ' O 0N 00 4.- 'N '1 0 N--'0 0 . 0.

_ 0 ".00N'0o 0 N N'."b

:- . .0 LO- N o, 0
=3 ." 0Ne5

, I-. O., _ l' _ 4-

35 0 j . 401 0e Xq 4. -NNeNN XV
.0. '1

6 4.;'D Q N _ 0 y . 0 "'0,_

'0 tOetX0 qN 4. N 0 N '0. e 0v._ 0

...... ....g...... ....

Ze=r 2 15 B Xa
. 5 .Z 5Z.4r 2
. 3_cOS_, 5gCCC.0
0 O0.5_ X:_:_v
' ' 0 v00 _ 2v o O ,
. C , vD w
' C-c'VGava== -0.C
0 , S _ ',, : Zz 4 ,_.

I-:

K-

r
3:Z

324

HANGING ROCK IRON REGION.

It will be seen from the above table that, with the exception
of two furnaces, Hunnewell and Iron Hills. there is no very
great difference in the size or general details of construction.
Hunnewell Furnace is also built on the same model, but is
larger than usual.
Iron Hills Furnace is, however, constructed on an altogether
different and more modern pattern, and one sufficiently novel
for this region to deserve a special description.
The furnace has an iron shell stack resting upon iron pillars,
fire-brick hearth and lining or inwall, closed top with bell and
hopper charging apparatus, and a gas flue for carrying the
waste gases to the boilers, which are situated on a bank about
twenty-five feet below the top of the furnace. The boilers
are situated upon the same level as the stock bank, and an
inclined plane elevator is used to hoist the charges to the fur-
nace throat from this level. The hot blast, which is of the-
Hoop patent, is situated at the end of the boilers. The fur-
nace was built to run upon the Lambert ore, which has been
already described. It started at a very inauspicious time for
a new enterprise of the kind, the winter of i873-'74, and was
compelled, through financial troubles, to cease operation in the
following spring, after having made only nine hundred and
sixty-two tons of iron. Since that time it has been idle, but
it is to be hoped that it will not long remain so.
It has been freely charged that the lack of success of the
furnace was due to the novelties introduced in its construction:
notably the substitution of gas flues for taking the gases
down to the boilers instead of placing the boilers over the
throat of the furnace, in accordance with the time-honored
custom. There is certainly no reason why this plan, which has
been successful at other places. and which is being introduced
in the latest and most improved charcoal furnaces in other
regions, should not be successful here also. If it has not been,
it may possibly be due to defective construction, improper size
of flues, insufficient draft, or some other similar cause; but
there certainly is no reason why the gases from a charcoal fur-
nace cannot be taken down through flues and then consumed
325

THE IRON MANUFACTURE OF THE

in heating boilers and hot blast as well as those from a coke
furnace. There is no- material difference in the composition of
the gases.
In working the furnace it was found that the hot blast ap-
paratus never was heated sufficiently to give a temperature to
the blast of more than three hundred degrees to four hundred
degrees, and it usually was about two hundred degrees, hardly
warm enough to be called hot blast. It is not unlikely that
the situation of the hot blast apparatus at the end of the
boilers is too far from the place of combustion, which princi-
pally takes place where the air is first admitted under the
boilers at the end nearest the furnace and farthest from the
hot blast stove, so that in reality it receives little more than
the waste heat from the boilers, all the combustible portion of
the gases being consumed before reaching it. It is probable
that if the hot blast apparatus were placed nearer the furnace,
with a separate flue to conduct a portion of the gases directly
to it, there to be consumed, it would be found as effective as
desired, and, with the furnace working properly, there would
be abundance of gas for both blast and boilers.
Of the charcoal furnaces in this region, Boone, Buffalo, and
Laurel run a large portion of the time, or altogether, with
cold blast, for the manufacture of car-wheel pig iron. The
remainder use hot blast all the time. The average yield of
the ores is generally stated by the furnace managers to be
thirty-three and a third per cent. of iron, thus requiring three
tons of raw ore for the production of one ton of iron. The
figures, however, taken from the stock books at seven furnaces,
for periods ranging from one to five years, give an average
yield of 3I.94 per cent., thus showing that it has been slightly
over-estimated.
It will be noticed that the averages for the different furnaces
do not vary greatly, three per cent. being about the limit.
This shows the general uniformity in quality among the dif-
ferent ores. Those furnaces situated west of Little Sandy,
and which use more or less of the lower block ores, show
the least average per centage of iron, while those using the
326

HANGING ROCK IRON REGION.

limestone and kidney ores show the highest yield. It will also
be observed that the average yield shown by the furnaces is a
considerably less per centage than indicated in the analyses
of the ores which have been given heretofore. This is due to
no fault of the analyses; they show accurately the composition
of the specimens submitted to the chemist. The discrepancy
is due to the following causes ist. To the loss of iron, which
often attends the working of the furnace, through the combina-
tion of iron with the slag. This loss is not constant, but is
greater as the furnace is working more irregularly and produc-
ing more mill iron. In such case there is usually an appreci
able amount of iron in the slag. As the amount of slag is
often greater than the iron produced, a very small per centage
of iron in the slag involves a considerable loss, and materially
reduces the yield of iron. This loss amounts to little or noth-
ing when the furnace is working well and producing a foundry
iron; for as the pig iron is not pure iron, but contains from
five to eight per cent. of foreign matter, carbon, silicon, phos-
phorus, &c., the gain by these impurities will more than coun-
terbalance the loss by the iron in the slag. In fact the furnace
working should show a gain over the analysis when every-
thing works properly. 2d. To the inaccuracy in selecting sam-
ples for analysis. The difficulty of selecting perfectly average
samples of ores has been already referred to. The method
adopted has been to take a great many small pieces of ore,
each broken from a different place in the pile or outcrop to be
sampled from, until the whole should amount to four or five
pounds. The endeavor has been in every case to obtain as
near a representative average sample of the whole as possible;
but it is probable that, in the majority of cases, it has been
actually taken better than the average. The personal equa-
tion in the matter of sampling an ore or coal is of great im-
portance, and it almost invariably works in favor of selecting
the best specimens, in spite of the fair intentions of the sam-
pler However careful he may be, he will be apt to think that
it is unfair to take a sandy or cherty lump of ore or a piece of
pyrites in coal, lest it be more than the general average of the
327

I I

THE IRON MANUFACTURE OF THE

bed. It is a singular feature of human nature, but it exists in
every one, whether personally interested in having the ore or
coal well represented or not. In addition to this personal bias,
it is usually the case that the ore sampled is cleaner and freer
from adhering dirt and clay than the average as it is weighed
at the furnace scales. This is caused by the sampler usually
selecting a clean corner on each lump to chip or break his
sample piece from, as he naturally thinks it would misrepre-
sent the ore to take a piece covered with dirt or clay. There
is no doubt that the per centage of iron is materially reduced
from this cause below what it would yield if the ore could be
purchased clean.
Notwithstanding all this, it is believed that the samples of
both ores and coals which have been selected for analysis by
the different members of the present Survey, approach more
nearly to the character of true representative samples than
any which have ever before been collected in this State or by
the Geological Surveys of many other States. The character
of the sample is of as much importance as the accuracy of the
analysis, if a true estimate is to be formed of the quality of
an ore or coal; and it should be held as requisite for the sam-
pler to be conscientious and unbiased, as for the chemist to be
skillful and accurate; and the name of the sampler should be
given as well as the chemist. It is because analyses are so
often made from small picked specimens representing the very
best of the ore or coal, that so many practical men consider
an analysis of no value, and charge upon the chemist the fault
of misrepresentation which belongs to the sampler. This mat-
ter is more important, if possible, in coal than in ore analyses.
The difference which there is between an analysis made
from a single lump taken from the center of a bed of coal or
from that part of it which is freest from sulphur, and one made
from a sample taken by making a number of cuttings through
the whole thickness of the bed representing the coal exactly
as it occurs, is very great. In the majority of cases heretofore,
the former is the kind of sample which has been subjected to
analysis.
328

I 2

HANGING ROCK IRON REGION.

The average consumption of charcoal per ton of iron in this
region ranges from one hundred and forty-five bushels, at some
of the best hot blast furnaces, to two hundred and thirty at
some of those working cold blast.
The figures from the books at nine furnaces, for periods of
time from one to five years, give an average for the whole of
one hundred and seventy-nine bushels per ton of pig iron.
This requires for its production about four and a half cords of
wood, estimating the usual yield at forty bushels of charcoal to
the cord of wood. The original forest of this region yields
from thirty to fifty cords of wood per acre, with an average of
perhaps thirty-five. Each furnace consumes from five thousand
to fifteen thousand cords of wood per annum, varying with the
length of the blast, thus clearing from one hundred and forty
to four hundred and thirty acres of land each year. In 1872,
as shown by the tables of production, there were made in this
region twenty-four thousand three hundred and twelve tons of
charcoal iron, which would require for its production the wood
from over three thousand acres of land.
It will thus be seen how rapidly the forests are being
destroyed, and how it is that only those charcoal furnaces
which are situated on the very largest estates, those of from
twelve thousand to fifteen thousand acres and upwards, can be
permanent, as they alone afford time for the second growth to
attain a size sufficient for charcoal-making before the original
forest is exhausted. It is evident, therefore, that in course
of time the charcoal iron industry of this region must be sup-
planted by the manufacture of iron with stone-coal, while the
charcoal furnaces will be built further back from the river,
where the forests are as yet comparatively unbroken, and from
whence the more valuable charcoal iron will bear the higher
cost of transportation.
The following table shows the average yield of ore, and the
consumption of charcoal, at most of the furnaces of this region.
The returns are not as complete as could be desired from' all
the furnaces, but the number of years from which the averages
329

I 3

THE IRON MANUFACTURE OF THE

are made is given in each case, so that the proper weight can
be given to the comparative returns by the reader.
In many cases the figures from which this table was con-
structed were taken directly from the furnace books, which
were kindly placed at the disposal of the Survey. The returns
of charcoal consumption are not absolutely accurate for com-
parison, as there is some variation in measurement at the
different furnaces. The charcoal receipts are given in loads
of two hundred bushels each, but the size of the wagon-beds,
which are counted as holding two hundred bushels, varies
somewhat at different furnaces. The consumption of charcoal
was of course taken at the furnace measurement in each case.
It is believed that this error will not amount to more than a
few bushels in the general average. The returns of ore are
probably accurate.

Number Ave'ge per cent- Number Average bushel,
Furnace. of years. age of iron in of years. charcoal to ton
the ore. of iron.

Bellefont..... . .. .. .. .. 4 32.23 5 185
Buena Vista..... 2 33 5 5 141
Buffalo...... . .. .. .. .. I 30.6 3 229
Hunnewell.... .. . .. .. .. 5 32.38 5 i6i
Kenton.... .. . .. .. .. .. 4 32.8 4 197
Laurel. ............... .... ....... 4 175
Mt. Savage . . .... . ..... 3 164
Pennsylvania.... .. .. .. . 5 31-7 5 194
Raccoon... .. . .. .. .. . . 4 304 l 163
Average... .. . .. .. .. . .. .. 31.94 .. .. 179
Furnace working cold bta. much of 6.e time.
The ores of this region usually contain such a mixture of
ingredients that comparatively little lime is required to flux
them. This is usually obtained from either the sub-carbonif-
erous or the ferriferous limestones. At Mount Savage Fur-
nace some limestone is used from the fossiliferous beds of the
middle coal measures. The amount used varies from two to
twenty-two per cent. of the roasted ore charged, as will be
seen by the following table showing the ordinary charges, or
so-called half charges, in use at the different furnaces. These
are given as they were reported, without any guarantee as to
330

HANGING ROCK IRON REGION.

the accuracy of the weights or measurements. It is probable
that the weight of ore is usually pretty correct. The weight
of limestone is, in many cases, estimated; and in the measure-
ment of the charge of charcoal, considerable differences exist
among the various furnaces; to reconcile which, in tabulating,
no attempt has been made. The following table is, therefore,
most valuable as showing the proportion of limestone used at
the different furnaces, as the ores vary:

AVERAGE -HALF CHARGES" USED AT THE DIFFERENT CHARCOAL
FURNACES.

Roasted ore. Limestone. Charcoal. Average num-
Name of Furnace. ber of half
Pounds. Pounds. Bushels. chrgesin 12

Bellefont.... .. . .. .. . 1000 20 33 .
Buena Vista..... . .. .. . 1700 20 33Y,
C-. B-... .. 75o 100 30 26
Buffalo .H. .. 950 125 30 28
Hunnewell... .. . .. .. . 1500 60 40 30
Iron Hills........... . 1200 225 335 .
Kenton..... . .. .. .. . I io 240 22 36
6o o100 22 38
900 60 22 45
Mt. Savage..... - 1050 40 25 30
Pennsylvania......... . 1250 60 35
Raccoon.... .. . .. .. . 1000 200 28 26

It will be noticed from the above table, that those furnaces
situated west of Little Sandy river, working considerable quan-
tities of the silicious lower block ores, use the largest per
centage of limestone. Kenton Furnace, which is compelled
to use more of these ores than any other, also consumes cor-
respondingly increased amount of lime. Iron Hills Furnace,
working the Lambert ore, shows its silicious nature by the
amount of lime which it was obliged to use. The furnaces, on
the other hand, which work the upper limestone and kidney
ores, consume a very small amount of lime, only ranging from
two to five per cent. of the amount of roasted ore.
The ore is prepared for the furnace by a preliminary roast-
ing or calcination. This is, as yet, done altogether in open
heaps or piles, so-called kilns. The fuel used is charcoal
331

THE IRON MANUFACTURE OF THE

braze, fine charcoal, which is pulverized in the manufacture
and handling. The ore is piled in pyramidal heaps upon a
framework of logs, in alternate layers of ore and fine charcoal.
The pile is then ignited at the bottom, and allowed to burn
until the charcoal is all consumed, which usually occupies sev
eral weeks, when the ore is screened from the ashes and dust,
and charged in the furnace. None of the furnaces as yet have
roasting ovens or furnaces. This process, as usually conducted,
probably offers more room for improvement than any other
feature of the iron metallurgy of this region. It is open to
serious objections, not the least of which is, that there is no
control over the operation after the fire is once started; the
whole success is dependent on the judgment of the man who
"sets" the pile; if he properly arranges it and distributes the
necessary amount of fuel, the operation will go on success-
fully; if not, there is no help for it, until the pile is all burned
out. It is extremely difficult, if not impossible, to roast all por-
tions of the ore alike. The interior of a heap is apt to become
too highly heated, while the exterior may be scarcely warmed.
There is great danger also of looping or melting the ore
before it is roasted. This is quite a serious injury to the ore,
rendering it more difficult to smelt, and materially increasing
the liability to loss of iron in the furnace, through its entering
into combination with the silicious matter present, forming sil-
icates of iron, which are apt to go into the slag. Looped or
melted ore is more difficult to smelt, as it is so dense and
compact that it is impermeable to the reducing gases of the
furnace.
These features are inherent to the system, and no care can
entirely remove them; but the custom of roasting many differ-
ent kinds of ore together, putting in one pile hard carbonate
block ores and shelly limonite kidneys, without regard to the
fact that they require very different treatment, as is often done,
adds another and probably the strongest objection of all. It
is a question whether roasting in open heaps is a method
suitable for carbonate ores under the best circumstances; but
nothing can be more injudicious than to pile indiscriminately,
332

HANGING ROCK IRON REGION.

into one heap, a mixture of carbonate and limonite ores, and
then expect to roast them all suitably at one operation. The
result is, that if fuel enough be used to properly roast the hard
carbonates, the limonites are looped; and if the heat is regu-
lated for the limonites the carbonates will be scarcely affected,
and require another treatment. Moreover, the carbonate ores
usually contain more sulphur than the limonites, and for this
reason they should not be roasted together, as the sulphur
escaping from the carbonates is apt to impregnate, more or
less, the other ores. This method of roasting is not an effect-
ual one for the removal of sulphur. This can be much more
thoroughly accomplished by the use of permanent roasting
ovens or furnaces, in which the process can be under complete
control, and the heat easily regulated according to the charac-
ter or requirements of the ore under treatment.
The present inability of the charcoal furnaces to use the
hard blue carbonate ores, and continue the regular production
of a coarse-grained foundry iron, has been already referred to.
We thus see that by far the greater proportion of all the
ore in this region is practically unavailable. If this is ever to
be used by the charcoal furnaces, it must be after an improved
method of roasting is introduced, by which the sulphur can be
effectually removed, and the ore, instead of being looped or
melted together, as at present, can be roasted with the admis-
sion of air enough to convert it into a porous, easily reducible
peroxide.
At present it is regarded as a finality by many furnace man-
agers that the blue ores cannot be worked to produce a hot
blast foundry iron, and they are therefore abandoning large
quantities of excellent ore of this kind, or else using it in the
production of cold blast iron, in which a light color or fine grain
is no objection. Where this kind of ore is used and roasted
in the ordinary manner, it is sometimes found necessary to
roast it two and even three times, before it is all converted
into peroxide and ready for the furnace. The bad economy
of this operation is readily seen. Any improvement, therefore,
which will enable this vast amount of now useless material to
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THE IRON MANUFACTURE OF THE

be utilized, will add materially to the wealth of this portion of
the State.
The introduction of roasting furnaces and an improved and
more intelligent conduct of the process, might not, it is true,
completely accomplish this result; but it. is an experiment
which can be easily tr