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THE HISTORY AND CONSTRUCTION OF THE DRY COLOR 770RK3 AT MUIBKIRK,
Jon/i I ■
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The original furnace at Muirkirk, Maryland was built by William and
Elias Ellicott in l%kj 9 It was bought together with the ore lands in IS 55
by William E. Coffin, an iron manufacturer of Boston. In 1864 the furnace
was taken over by nis son t Charles E. Coffin, who operated it until I9O9
when he leased it to his son, Ellery F- Coffin, who ran it until I91U. It
was in the hands of the latter 1 s three sisters ana his cousin for two years,
then was leased to a Baltimore eomnany who failed to Lake it pay. It was
bought in I923 by E. M. and F. Waldo who have operated it since then as a
dry color works.
The first furnace built was of the hillside tyue and was replaced
by one with a hoisting elevator to load it with. The plant was rebuilt
and enlarged after an explosion in 1SSQ* The old charcoal kilns and the
ruins of the storage bins and ore ovens can still be seen*
The iron made at Muirkirk was the best in the country and much of
it was bought by the United States govenorment. The pigments unade there .
now are used in paints, rubber, cement, composition shingles, and a
variety of other articles.
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At Muirkirk, in Prince Georges County, Maryland, is an east and
west road which crosses the new Washington, D- C. and Baltimore boulevard
and the Baltimore and Ohio Railroad by a long bridge of limestone, concrete,
and steel* It is at the junction of these two roads that the dry color
works are located, just fourteen miles from Washington, D. C*
The plant is now owned by 1, M* and F. Waldo, who are engaged in
the manufacture of dry color pigments* It is on the site of a large old
iron furnace that manufactured this metal from ores obtained in the
The old furnace called Muirkirk goes back to 1S^7, when it was
set up by a member of the Ellicott fsmily. Legend has it that Major
Nicholas Snowden cajne to America from Wales about I7U0 and brought with
him an iron furnace and equipment. The location he chose to set up his
furnace was very close to the later plant, and its ruins may be seen
today. Just when this iron plant was established and how long it oper-
ated are not definitely known, but it is certain that it was running
during the Bevolutionary War and for a time afterwards.
The furnace built in 1S^7 by the Ellicotts was one of those crude
affairs known as a hillside furnace. The pig iron produced at Muirkirk
became widely known and celebrated for its fine qualities. It was in
18 55 that the furnace and ore land belonging to it were bought by William
E. Coffin, a New England iron manufacturer. He had come to know of the
furnace through its distinction in the iron trade. Mr. Coffin and Enoch
Pratt were friends and while visiting Mr, Pratt in Baltimore, Mr. Coffin
learned that the furnace and its lands were for sale. He bought them.
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Three generations of the Coffin family have operated the property,
William 32. Cofi in, his son, Charles E. Coffin, and his son t Ellery IT*
Coffin; the latter is still living. According to the Rambler in the
Washington (D.C) Evening Star, Charles E. Coffin was widely known in
southern Maryland and in Washington, He was a Republican leader in the
state for thirty odd years , and he served in both branches of the state
legislature and also two terms in Congress. He was an important political
figure as well as a manufacturer.
William E. Coffin actually operated the plant only a year. Prom
the time he bought it until 1862 it was leased out* The next year, 1S63,
the plant was taken over by George R* Burroughs and Charles E. Coffin.
At this time the weekly output was 33 tons of pig iron. By enlarging the
plant the output was greatly increased. In 126*+ Burroughs sold out to
Mr. Coffin who became sole owner and operated the furnace mi til I9O9 when
he leased it to B- F. Coffin and Company whose lease expired in 1911. Mr.
Coffin said that by improvements in manipulations, he increased the weekly
output from 120 to 1^0 tons, without changing the size of the furnace
stack. It remained in constant ooeration until IS/U, since when it has
been operated only enough to suuoly the demand for the high grade of char-
coal iron made there.. Tnis last date marks the t>eak of its (Sareer. At
that time the Muirkirk plant was the chief industry of southern Maryland.
It gave employment to a large mmber of people, the greater oaxt of them
colored. Today many of these old iron workers' homes are still occunied
by descendants of the sa^e colored people.
In 1SS0, an ex-plosion in the furnace burned down the plant, and in
rebuilding, the height of the stack was increased from 28 feet to 36 feet.
In a report on "The Physical Features of Maryland, 11 issued by the
Maryland geological survey in 1906 is foand this:
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■'The only furnace manufacturing Maryland iron to any extent is the
Muirkirk furnace in prince Georges County- It employe very largely the
carbonate ores which are obtained from the Arundel formations, mainly from
Anne Arunde and Prince Georges counties, These great lenses of carbonate
ores have been worked since early colonial days, but an ample supply still
Under the same title in igil f the Maryland geological survey report
has this to say:
"The pig iron produced at Muirkirk has long been known for its ten-
sile strength, and for this reason it cormiands a higher price than any
other pig iron produced in this country- There is a. ready market for the
product, which is used exclusively in the manufacture of special articles
in which great strength is required. It has been used extensively by the
United States Government in the manufacture of cannon, and is also in
demand for car wheels, cylinders, and special kinds of steel. The claim
is made by the proprieters of the furnace that their product is the strong-
est pig iron produced in the United States. The slag has been used as road
isetal in the vicinity of Muirkirk and at the present time is being shipped
elsewhere for this propose."
It is interesting to note at this point the three letterheads
appearing on the next page; the first one, Pig* 1, dates back to 1S&3
when William E* Coffin was operating the furnace, Fig- 2 is the letterhead
of Charles E* Coffin, who ran the plant at its peak, Fig, 3 is the last
one and looks quite modern as indeed it is, only dating back to 1912*
Still more interesting are the claims and inscriptions on each one* The
first one bears a list of the numerous other products and interests of
William E. Coffin at the time he acquired the Muirkirk property. The
second shows an old engraving of the plant with its railroad siding, as
mli , Wh/v,
///. f< .
STEAMBOAT, RAILROAD AND OTHER FORGING
iKE BAB IROS (ALL -i/
PEMBROKE BOILER ANT' TANK RIVET&
STATE OF MAINE CO NAIL-.
SHIP ANP l:Ai:
AMERICAN AM PIG IRON.
;s f ri.w ANH KAOLIN
PORTABLE tfTEAM ENGINES.
RIVET IRON, SWARF IRON, SIluK SHAPED
MUIRKIRK, CHARD IRON,
AMERICAN BOILER AND TANK IRON.
loir : FELT.
FAS BLOWERS— CAR AXLES— AHCHQB&
UTINCi IRON CUT Ti> LEI
REFINED 11AR IRON.
TELEGRAPH STATION, LA US EL, MD.
/ Ml IKK IKK < II UK OAL VUi I KO\
<iefs - avcrac! or a pieces ko.4 Fie-gfoa* Cm
RIEHLB » R0S P^iU-ADEtPHiA.
^-^hjemb or 4PDraa b .4 no -«orn iiBS.*s<*.ttCft-
ROGERS. BROWN ft COMPANY
CICLUIIVE **Lt« ASINT*
The Muirkirk Furnace
ELLERY F, COFFIN
MUIRKIRK CHARCOAL PIG IRON
The Strongest Pre Iron in the United States
CtflTirica Pm T«st» of 40.000 to CO.OOO Lri. TO tO> In, TisciLt Strength
USED FOR MANY YEARS BY THE U. S. GOVERNMENT ARSENALS AND NAVY
YARDS FOR CANNON, MORTARS. GUN CARRIAGES, GUN IRON CASTINGS
AND OTHER PURPOSES. ALSO IN DEMAND FOR CAR WHEELS. CYLIN-
DERS. PLOW SHARES. LOCOMOTIVE CASTINGS, CHILLED ROLLS. ETC
OFFICE AND FURNACE AT MUIRKIRK. MD.
ROA8TCO CAR BON ATE
Telegraph Station Muirkirk, Md
Muirkirk. Maryland, C-P ,
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well as results of tests of the tensile strength of their pig iron. In
those days as well as today forty to fifty thousand pounds per square inch
indicates exceptionally good iron. The third letterhead shows a long list
of sales offices that might well grace a larger company, also a list of the
uses of their product.
Ellery F. Coffin oners ted the plant until 1913* At this time, he
deeded it to his three sisters and his cousin Mr. Jones* They ran it
under the name of the Muirkirk Iron Corporation for two years. At the
end of this time they leased it to Messrs. Powell, Carroll Brown, and
Henry Williams who formed the Muirkirk Iron Company . Due to the high cost
of charcoal at the time, they tried to run the furnace on coke made in the
old charcoal kilns of the plant. The furnace was not of the type that would
use coke and would clog up constantly* Because of this the last iron
manufacturing at Muirkirk lost money for its backers, and they gave it up.
The property, the furnace, kilns, ovens, and ore "beds were purchased
in 1923 by E. M* and F. Waldo of New York, who were, and still are, engaged
in the manufacture of dry color pigments made from iron ores and other
materials coming from the earth. The reason for their buying the plant
was simple* One of their largest customers was a well known manufacturer
of roofing shingles made from a composition, Waldo brothers supplied him
with the pigments to color his shingles, and one of the most predominant
colors was brown. It so happened that the ore beds of Muirkirk contained a
quantity of hematite from which the brown pigments could be made. Hematite
is an ore of iron containing iron oxide in the form of Fe2&z, Jhe color
made is known as metallic brown and is one of the cheaper shades* The
plant was ideal for the making of this pigment since the only additional
things necessary were small mills for grinding and bins or vats for mixing.
The kilns were used for roasting whenever necessary. The old furnace,
however, was of no use at all, it was torn down. It had been so well made
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that dynamite was used to demolish it. At this time, ig23» the Waldo'
brothers had another plant at Harmon, Maryland, one in Tirgiaia, and two
in New York State* Now, at the present time, because of the dropping off
of the demand for these figments, the company has closed down all of the
other slants and only operates the one at Muirkirk. The ores and other
ingredients are shipped in, mixed according to formulas, imt in suitable
containers, and shipped to the customers. The ore beds belonging to the
plant are no longer worked because the products can be imported cheaper
than they can be mined. This is due to the high cost of labor and the low
quality of the ores.
Fig* k Fig. 5
The above photographs are general views of the present olant. Fig.
4 shows the building used for crushing the ores in the left foreground,
while just to the right of it is a roof covering some barrels of finished
pigments ready to be stored in the warehouse to await shipping. Behind this
roof is a large tank for the storage of weter- In the background is a tall
structure resembling a grain elevator. It is trie old tiople for lifting the
the ingredients to the top of the furnace. The small building in the fore-
ground of Fig- 5 is the chemist's laboratory, behind it can be seen the
tipnle and the stack of the ros sting oven which is also visible in Fig. 2,
The buildings dimly seen to the right and rear of the laboratory once housed
the machinery and steam engines, necessary for the power required for the
operation of the plant.
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The original Muirkirk Furnace, a stea^ hot blast charcoal furnace,
was built in 1S^7 by William and Ellas Ellieott, owners at that time of the
Patuxent Furnace in Anne Arundel County. It was twenty-eight feet high and
eight ani a half feet wide at the boshes, and of the type knovm as a hillside
furnace* It was built on the same plan as a famous furnace at Muirkirk,
Scotland. The stack itself was erected right against the side of a hill.
The ore, charcoal, and other charges necessary were brought up the hill in
wheelbarrows or wagons and dumoed right in the top of the furnace* The
molten iron was drawn off at the bottom through suitable openings and run
into pig moulds where it was allowed to cool and harden. The weekly output
at this time was thirty- three tons of pig iron,
When Charles E- Coffin took over the plant he enlarged it and thus
increased its output* He built six more charcoal ovens like the one shown
in Fig;. 6. A corner of one is also visible in the left foreground of Fig*
7- These six are the only ones left standing of twenty that were there*
The other fourteen were older and of the size and shape shown in Fig- 7.
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These charcoal kilns lie in the field soutn of the furnace and are
visible from the road. The old kilns were about thirty feet in diameter
at the bottom and rose in the shape of a cone to a point at the top. They
were constructed of fire brick on the inside and ordinary clay brick on
the outside . The six that are now standing are of a different shape and
more nearly resemble a coke oven* The walls rise almost vertically to a
dome-like roof. The walls on the outside are built of stone blocks and the
dome of brick. The inside is lined with fire brick* Rectangular holes
are visible at the bottom to permit air to enter and circulate t and to
regulate the amount necessary for the burning of wood to charcoal. The
kilns at the bottom are thirty feet in diameter, as were the old ones. The
wood was cut nearby and hauled to the kilns. Sometimes the wood was burned
right where it was cut end the charcoal hauled to the storage bins.
There were two of these bins, one for charcoal and one for ore. They
were at the south end of the furnace right on the edge of the field contain-
ing the kilns. Only the stone foundations are left of these structures, but
they show that the bins themselves were large and give one an idea of the
size of the old plant. Some distance east are ruins of the old brick ovens.
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Close to where the old stack was, is a great cistern — shown in
Fig. 2. There were a maze of water pipes connecting it with a well and a
pump, This water plant was used for cooling the outside of the stack to
aid in the ^reservation of the walls, for the combined fluxing and abraid-
ing action of the descending charge tends to wear the lining at its hottest
part # near the lower end* By cooling the outer walls the life of the
lining was increased as was the efficiency of the furnace- The pump and its
connecting pipes have long since disappear ed, but the cistern is very much in
evidence with stout iron bands encircling its sagging walls.
The old stack was behind the cistern and to the right of the tipple
shown in Fig. S# It was rebuilt in IS 80 after an explosion in the furnace
burned down the T)lant t and in rebuilding the height of the stack was
increased to thirty-six feet. It was blasted down with dynamite when E. M*
and F* Wfldo took over the plant as they no longer had any use for it*
The roof of the casting room is visible in the same picture behind
and to the left of the cistern* It was here that the molten iron was run
into the moulds and allowed to cool. At a certain period in the cooling of
the iron the heat is dravm inward instead of outward t and the story is told
of how a huge negro, working in this casting room, would walk on the hot
iron in his bare feet or hold a niece in his hand. Because of this seem-
ingly supernatural feat he was held in awe and terror by the rest of the
colored people in the community.
In the foreground of Fig. 8, directly behind the railroad tracks is
a small shack that covers the well and houses a small pump to supply the
nresent water suoply* This was also the location of the old pump.
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fig, 9 is & view of the old air tank, now used to store water.
It was used to suoply the hot blast to the furnace.
Fig, 10 shows the warehouse and railroad aiding of the present
plant * The freight car ore sent has Just been loaded with bags of the pig-
ment s. The concrete t>iles shown in tue picture of the charcoal kiln, Fig.
6, are the same as the ones used to support the warehouse and were laid
with a view of enlarging the warehouse if it ever proved necessary.
The old kilns for roasting the ore are now in ruins t but there were
six of them* At the time Sllery F* Coffin ran the furnace, two were used
to burn the white or carbonate ores and four for the hematite ores.
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Under this heading come iron and pigments since these two items are
the ones associated with Muirkirk. Of the former there is not much more
to be said- The furnace at Wairkirk would probably be running at full
"blast if steel had not risen to the present t>laee it now occupies in industry*
With the coming of steel there was iDractically no demand for the high grade
of charcoal iron turned out at Muirkirk, It cost more to make* but it was
the best that could be bought. Wany steels manufactured today do not nave
the strength it did- Its uses were many and varied as can be seen from the
letterheads- An examination of the fracture of a specimen of the iron that
was pulled apart in a testing machine revealed a close grained structure
that resembles high carbon steel; the dete staged on the end is 177^-
The present dry color works can sumly you with any color pigment
you desire and for almost any use you could wish to put it. AH the pigments
made from iron oxide contain it in the Je2®~$ form together with other mineral s.
Metallic brown, the first pigment turned out by this olaiit contains manganese
in addition to the oxide. It is used in cheap paints mostly for freight
cars. The color is not as durable and lasting as the umbers t another line of
brown nigments. They contain about thirty-six per cent of oxide and are
imported from Turkey* Venetian Red is another color containing gypsum as
well as forty to fifty per cent of the oxide. One pound of this will color
six gross red rubber rings used on Mason jars, and this is its chief use
together with the coloring of other rubber products, French ochre, raw and
brunt siennas f and the green chrome oxides are other colors. Many pigments
hpve been sold to cement manufacturers to color their products. There is a
cemfcnt path from the office to the laboratory that is colored with brill isnt
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"blue, red, yellow, and orange, showing some of the experimental work done
in this line.
In the laboratory one whole side of the wall is covered with shelves
containing jars of the various colored pigments # For every color on the
shelves there are a do 2 en or more shades* Whenever & color is desired it is
first chosen from one of the jars, then the shade decided on, and the
fo.raula for the ingredients looked uo in the files* The latter are now
weighed from their respective bins, mixed and put in heavy ^aper bags, and
there is the right color of pigment already to "be shipped to the consumer.
Tfie only things being done at the plant now are the grinding, mixing, and
occasionally the roasting of the -oigments. Everything used is shipped in;
the old ore "beds are not worth working.
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The data for this thesis were obtained from;
Harry Shannon writing as the Barribler in the Washington (D.C.)
From interviews with;
Mr* Jones postmaster at Muirkirk, Maryland ai*d at one time
operator of the iron furnace,
ttr. 3 co we, chemist at present dry color works,
Mr* tfaldo one of the present owners,
Ut* Ellery F. Coffin one of the former owners,
And from the files of the Maryland ^hiea^ survey for
1906 and 1911. ^juL^