THE MTJIRKIRK IRON WORKS.
This recort or. the Muirkirk Iron Works if? of
imnortanee "both because of its location in the State of
Maryland and tae fact that it is a typical example of an
industry that hae almost massed into history. Its loca-
tion in the State of Maryland at once set 3 it apart in
the iron- producing field as one of the first in the qual-
ity of its product. The furnace shut do-ra in IS 30, there-
by closing the history of charcoal iron-making in the State
of Maryland, It was the last of its kind in the State,
but it was iuolicatei in every section of the United States
at about the time of the Civil War.
These hillside furnaces rendered valuable aid to
i Colonies' during the "evolutionary l Var. The cannon,
an! the shot to fire in the cannon, were cast of charcoal
iron. Later nails and clows were male. "Soma of the
veterans of the cupola will recall the time when a sugges-
tion to use aught but cold-blast charcoal metal for car
wheels was considered approached to criminal intent, as
human life might be at stake. " But due to cheaper trans-
portation and manufacture of iron by the use of coke instead
of charcoal, these little centers of iniuatry have shut
down one by one until now only a few remain.
This furnace, then, is worthy of note, although
not in operation at ©resent. So in the following cages
I have given a few facta concerning the history, location,
process of converting orea to pig iron, ani the troiuct of
the Muirkirk Iron fork*,
Paaaano's "History of Maryland" contains the
following caaaage: "The iron industry in Prince George's
(County) dates back over a century. The Snowdens, among
the original 33ttlers of the county, established furnaces
at various points in southern Maryland. The Patuxer.t
Furnace and Forge waa long a notable industry. The only
iron works now in o Deration in the county, or in rural
Maryland, is the Muirkirk Furnace on the Baltimore and
Ohio Railroad, at Muirkirk. It waa erected in 184? by
Andrew and Flias Fllicott and moislsi after a furnace at
Muirkirk, Scotland. " The shove article was taken from
the hiatory cocy righted in 1901. Going back to a time
before 184? *« fini in the "Maryland Geological Survey",
on The Physical Features of Prince George's County, that
Richard Snowdsn and George Yates bought for 11,000 nounl3
of tobacoo a tract of land called tlis Iron Mine on
January 11, 1669. In 1686 Richard Snowien patented
from the Proprietary of Maryland a tract of land which
he called "Robin Hood's Forest" and which contained about
10,500 aores. In 1683 Richard Snowden bought from Wil-
liam Parker a tract of land of 800 acres called "Good Will".
In 1847 th# Muirkirk Furnace was built near the old "Iron
Mine". This furnace was bought from the Ellicotts in
1860 by W. E. Coffin of Massachusetts. On the death of
f. E. Coffin his son Charles E. Coffin assumed charge of
the furnace. The last blast of the oil Muirkirk Furnace
was superintended by Ellery F^ Coffin, who lives at Eelts-
ville, Maryland, and who survived his father Charles E.
Coffin. The site of the furnace is now being used as a
It is interesting here to note that in "The
Iron and Steel Works of the Unite! States, " published
in 1833, by the American Iron and Steel Association, ap-
pears the following article, under Charcoal Blast Furnaces:
"Muirkirk Furnace; Charles E. Coffin, Muirkirk,
Prince George's County. One stack, 38 x 8.5, built in
1847, burnt and rebuilt in 1388. Open-top; ore, carbonate,
mined in the neighborhood, roastei and crushed before using,
pig iron used for car wheels,, guns, flange iron, and shot
and shell, annual capacity 7,000 tons net. Brand,
"Muirkirk". Selling agents, Robinson and Orr, Pitts-
burgh, Arthur W. Howe, Philadelphia, ani C. L. Pierson
& Co. , Boston. "
The Maryland Geological Survey of Prince George's
County, published in 1911, contains the following:
"The Muirkirk Furnace has besn in almost con-
tinuous use since 1847, and during that oeriod has pro-
duced a great quantity of high grade pig iron. After
having been closed for three years it was opened again
in May 1309 and i3 producing about 400 tons of pig iron
per month from about 1300 tons of ore. n
In the above accounts it will be noticed that
the Muirkirk Iron Works has been designated as first the
Iron Mine, second, Muirkirk Furnace, and now the Muirkirk
The Muirkirk Iron Works, formerly known as the
Muirkirk Furnace, is located in the northern part of Prince
George's County, Maryland. It is between Washington and
Baltimore, at a distance of about fifteen miles from the
former, on the Baltimore & Ohio Railroad and the new Wash-
ington and Baltimore Boulevard, which run parallel to each
other within a hundred yards to the west of the old furnace.
Dirt-S f&cf R oaf c}
About two mil 9 8 to the east is the oil Baltimore and
Washington Turnpike. Numerous ponds ani lakes within
a radius of five miles of the furnace indicate the exten-
sive mine operations of the industry.
The rough sketch on the opposite page shows the
relative location of the component parts of the Muirkirk
Furnace, which include the furnace, the charcoal kilns,
moulding room, crusher, blower, roasting ovens and office.
The picturesque kiln3 and part of the furnace can be seen
from the road and the railroad. The houses of the workmen
which were furnished by the operators can also be seen to
the right of the works.
Briefly, the process used at the Muirkirk Furnace
consist 3 i of mining the iron ore, cutting wood and making
charcoal, roasting the ore, crushing the ore, smelting the
ore, and moulding the nigs.
The iron ores in the vicinity of Muirkirk are very
lean. They are primarily iron carbonates, though many of
them have been altered to limonite or hematite near the sur-
face. "The Anne Arundel formation in Maryland has long
been known as the important iron-bearing member of the Poto-
mac group, and many mines have been worked in this formation
in Prince George's, Anne Arundel and Baltimore Count! 33.
In Colonial times these mines were of the greatest import-
ance, ana many of the cannon U3ei in the Revolution were
made from Potomac iron ores. In recent years, however,
these mines have decreased in importance, as most of them
have he en unable to compete with the Lake Superior ores,
and at the present time the only furnace using the ores
is located at Muirkirk in the northern part of Prince
George's County. The numerous immense pits now filled
with water that can he seen in this region furnish evidence
of the large quantity of ore that has been removed, though
the present operations are rather small. " (Md. Geo. Surv.
Pr. Geo. Co. 1911.) A3 is the case with iron mining all
over the United States, the mines were orien surface. After
stripping off the surface soil the ore was loaded on horse-
drawn wagons by negro labor. It was then carted to the
roasting ovens. Owners of the land were paid a royalty
for each ton of ore removed.
Sines charcoal was one cf the essential constitu-
ents in the making of the charcoal iron, it must be had in
large auantities. Wood was cut in the nearby forests ani
piled in the brick kilns which held about 45 cor is. A fire
was kindled under the pile and after burning a while the
open top of the kiln wag covered. Thus the volatile
matter in the unhurnt wood was driven off at the expense
of the burning wool. The charcoal was then removed and
was ready for use in the roasting ovens and the furnace.
This method of obtaining the charcoal was very wasteful
and expensive. Later it was found to be much cheaper
to buy the charcoal than to make it near the furnace.
Some of the charcoal kilns or ovens still remain
and are in a good state of preservation. They are of a
good quality brick. The shape is that of a half snhere
having a circumference at the ba3e of 100 feet. The floors
are of cobblestone. Two openings are oroviiei, one in
the top and one near the base. The accompanying photograph
gives a good idea of the beehive appearance of these charcoal
Originally the furnace had a number of roaeting
ovens, but they are in ruins now. There was a bank
of four of them placed si Is by side. The ruins indicate
that the walla were two feet thick and the dimensions of
the base of each was about ten feet by ten feet.
The process of preparing the ore and making pig
iron at Muirkirk wag similar to the method used in Eng-
land in 1400. In a little book called "Charcoal Iron"
by Dr. Richard Moldenke, is the following: "The early
years of 1400 found pig iron male in England, ^arsons
(1680) describes the roasting of the ore (calcining) by
mixing it with coal and filling up kilns similar to those
for burning lime, thus getting the ore ready for the furn-
ace. After lighting \ap at the bottom and burning away
the ccal mixed with the ore, the latter was removed and
the kiln recb.ar.gei. The very process can be observed
today at Muirkirk, Maryland (l930), whsre the siierites
(spathic ores) of that region are mixed with coke breeze
and calcined. The roasted ore then goes to the blast
furnace and makes an excellent charcoal iron. " After
leaving the roasting oven the ore was run through the
crusher, coming from the crusher about the size of fine
gravel. The ore was then ready to be mixed with the
charcoal and put in the smelting furnace.
The Muirkirk Furnace was 33 feet high and 8.5
at the base. It had a capacity of 7 tons. The main
part of it is of firs-brick and is still standing.
Alternate laysrs of charcoal, roasted ore and
limestone were placed in the furnace until it was charge!.
The charge was lighted and a cold blast used. The furnace
was icevt running day and night until the materials at hand
were exhausted. Every six hours the slag was drawn off.
About ten inches of sand was placed on the moulding room
floor. Channels were cut in the sand so that the melted
metal would flow to the long rectangular molds in the sand.
The channels are called sows and the rectangular bars of
iron, after the metal has cooled, are called pigs. The
pigs were about four feet long and were broken in half for
The 3 lag ani refuse from the furnace wa3 used
for road material, and Lb proved the roads greatly in that
section of the county.
The Muirkirk Furnace advertised its "Muirkirk
Charcoal Pig Iron" as the strongest oig iron in the United
States. It was used for many years by the United States
Government Arsenals and Navy Yards for cannon, mortars,
gun carriages, gun iron castings and other our coses. They
claimed it was also in demand for car wheels, plowshares,
cylinders, locomotive castings, chilled rolls, etc. Muir-
kirk iron was graded from 1 to 6. No. 1 had a tensile
strength (nig) of from 30,000 to 33,000 pounds per square
inch. No. 6 was white iron. No. 4-1/4 was the grade
which they claimed to be the strongest iron in the United
States. They say, "Muirkirk No. 4-1/4: Close grey grain,
chills against chill plate in pig bed from 1/8 to 1/4 inch,
tensile strength of pig from 38,000 to 41,000 pounds per
square inch, an I specially selected iron has tested as high
as 53,000 pounds per square inch." The last blast of Muir-
kirk pig iron was bought by the Cambria Steel Company.
John Thomas, superintsndent of the Thomas Iron
Company, Hokendauaua, Pennsylvania, November 16, 1883,
submitted the following report:
"Charles E. Coffin, Esa. , In the test we made
we cut the piece of pig in four parts in a shaping machine;
we turned two of them to exactly S/16 inch at the breaking
point, and got the following results:
" 1st: 50,730 oounds per square inch.
" 3nd: 53,160 pounds per square inch.
"I really don't know whether to believe it or not
as the tensile strength is so extraordinary, but nevertheless,
these are the results obtained by the machine.''
In ledger No. 40368. 16 of the itfuirkirk Furnace
appears the following item: "Iron sold and delivered
July Slat to January 31st, 1887, 591 tons, average price
$26.93, net proceeds $15,913.51."
The Muirkirk Furnace ha3 passed into history.
No more will the moulding room floor be filled with live
srarkling moving heat ag the melted iron flowed from the
furnace through the sows to the pigs. The furnace will
probably never warm to the heat of another blast. It is
empty and cold.
Soon only the name of a once thriving plant will
remain. "The foundry world has progressed in the mean-
while and a relentless deetiny has closed down most of
the furnaces which followed the pioneers of our rapidly
developing country and serve! their needs so faithfully. "
It was a typical hillside furnace, dear to the
heart of that rapidly passing group of miners who worked
their own furnaces. Scattered about are charcoal kilns
and negro shanties. The place had a generally run-down
appearance. The four roasting ovens are in ruins. Much
red clay dust blows about. This red clay is used in the
manufacture of paint, for which the plant is now being used.
(January 1935) The old family residence of the Coffins
still stands proudly near the once busy furnace. But its
shame is partly hidisn by the merciful trees, which sway
mournfully in the breeze.
The mighty "blast furnaces of today, using coal
coke, a hot blast, and operating in multiple, near heavy
veins of rich ores, have left the wasteful, forest-consuming,
charcoal furnaces far behind as a profit-making industry.
But the charcoal furnace was not to be beat in the quality
of its product. It is therefore of more than sentimental
value to the foundryman and the industry. Maryland may
well be proud not of the quantity of its iron production
but of the quality of the product of the blast furnaces
of which Muirkirk Furnace was a fins example.
Magruder Passanc History of Maryland.
Dr. Richard Moldenke .Charcoal Iron.
American Iron & Steel
Association The Iron and Steel Works*
of the United States.
Maryland Geological Survey Prince George's County, 1911.
Ellery F. Coffin Present owner of furnace.
John Brewer Former workman at furnace.
S. R. Church Analysis of Pig Iron.
Charles E. Coffin Muirkirk Furnace.
John Thomas Report on ten3ile strength.
Muirkirk Furnace Ledger No . 40368 . 16 .
Oli. charcoal kn na ,
Hsoent photograph of Ironworks.
Photograph of LHgT£0.t.^!LJll!lg.l2 _ln 1904
by Charles S. Coffin.
View of Ironworks from Charcoal Kilns,
b l*t*: V.
W. E. Coffin.
Charles E. Coffin.
Roast ins ^ ena._