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Full text of "History and method of operation of copper mines at Bare Hills near Baltimore, Md"

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f^Tf 72-*-— 



John A 



One of the first mines opened in this country 
with the rurnose of producing copper was the mine at Bare 
Hills, Maryland. The m3ne nroduced Biuall amounts of 
copper ore. At the start of the Revolutionary War, the 
mine ceased operations and remained closed until the year 
1845 when operations were resumed on a small scale. The 
mine started operations of a large scale in the year 186 
and continued operating with a lsr ge output until 1886 
at which year the mine was closed because of certain facto --s 

'.:■ h made operations difficult. In 19C0, new machinery 
was installed and the mine reopened and operated until 
1902. Since that time It has been ready to operate at 
several times but has never actually been operated. 

The Bare Hi 11 mine, while not running now, has 
considerable promise of ore; but the low price of copper, 
the smal";ness of the deposit and the cost of equipping; the 
mine with modern machinery will probably keep the mine 
closed forever. 



That Maryland was early explored for mineral 
wealth Is shov;n by a report on the Province, made in Dec- 
ember, 1748, by the Governor and Council to the London 
Board of Trade. After the discovery of copper ore at 
Bare Hills, a Mr, Jonathon Sleeman, a Corn! shman, bough 
the land with the intention of opening a "surface" mln< . 

■ject was soon abandoned, very little ore .-•. .- 
ly havj ng been removed. 

The mine was reopened by Thomas Petheriek about 
1845, but wis soon abardoned by him and taken up by a 

avis. Petherick had taker; the mine from the owners 
under a Gornish lease for twenty-one years, the lease 
beinc, of the same type that hns been used for centuries in 
England. He sold this lease to Isaac Tyson, Jr., a man 
who was attem] I ; to control all of the mines in Maryland, 
When Davis' lease exnired, Tyson endeavored to hold the 
property under this Cornish lease but after a lonq and 
hard-fought lawsuit, the decision was finally rendered 
that this form of lease was not binding;. The decision 
was due to technical points in the construction of the 
lease and the property went back to the original owners. 

sina; through several hands, the property came 
Into the c^.'ro] of the uare Hill Mining Company, 


'■Lhe mines had been worked previously to 1864, 
but in pany began Its most active operations. 

The officers of the company were William H, Keener, president, 
and Dr. A* P. Dulin, J. Hall Pleasants, John W. McConkey, 
C. Oliver O'Lonnell, and George T. Coulter, directoi-s. 
The capital stock was #500,000. In 100,000 shares. Pew 
mining companies have commenced operations und*r circumstances 
so favorable as those which characterized the Bare Hill Co. 

The richness of the vein was shot the state- 
ment of an expert, who r< that in the 600' level the 
ore was 180' long, 60 ' high, and 3' thick. The 

ie 500' level were 30' by 80' by 2 l/?', and in the 450' 
level 80' by rsO' by 2 l/£" . At this time there was In sd ?ht 
1000 tons of ore, worth at ruling prices $140,000. and the 
engineer added that bis only regret was "to find a mine, with 
such masses of ore exoosed, worked on too small a scale, 
and to meet a few miners where scores could find profitable 
employment". Another engineer calculated that #9,000, worth 
of ore per month could be sent to the market, and more 
recent investigators have given the opinion that the richest 
and largest deposits have never really been touched. 

According to Dr. Lehmann, of Baltimore, this mine 
was operated almost continuously from 1866 to 1886, the 
entire output going to the Baltimore Copoer Works, the 


sampling and assaying of the ore being under Dr. Lehmann's 
supervision. The records of both his office and of the 
copper company vie re destroyed by the great Baltimore fire, 
but the old samples, labels, and memoranda at hand enabled 
him to give the following rough estimate of the total out- 

Prior to 1866, the yearly shipments varied between 
2,000 and '5,500 tens of 15 to 20 percent ore. From 1866 to 
1876 the annual output was from 800 to 1200 tons of "cobbed" 
ore, averaging 18 percent copper, with 1,000 to 1,500 tons 
of "hutched" ore or concentrates. From 1876 to 1886 the 
shipments gradually lessened, being al 60 tons a month 
of 18 percent "cobbed" ore from 1883 to 1886. Taking the 
average of these figures, the total output from 1066 to 
1886 is about 32,500 tons of 18 percent material. At 15 
cents a pound for copper, this represents a gross valuation 
of $54. per ton, or a tota] value of $1,755,000. According 
to the Tenth Census, the mine in 1880 yielded 17 tons of 
concentrates, from which 1,275 pounds of copper were prod- 

The mines were profitably operated until 1886, 
when legislation by Congress in the special interest of the 
companies owning the Lake Superior Copper-Mines forced the 
Bare Kill corporation to suspend work. 


The mine was not in operation for the 15 years 
between 1886 and 1900. At the last named date a stock 

company waa formed to reopen the property, new machinery 
w-is Installei md the mine was unwatered. The mine was 
reopened to fill an order for copper sheathing for a fleet 
of ships operating to and from Pa] ti more, after the order 
was filled, there being no further orders in sight, the 
property waa sold under a deed of trust. 

In 1905 the mine was in the possession of I . 
Herbert Brown, who waa preparing to unwater and work the 
property. Having no orders in sight, Brown sold the mine 
to a Mr. Hill who left the mine to its present owner, 
Miss Elizabeth Hill. 


The deposit, according to old descriptions, was 
in a vein which carries calcopyrite, bornite, an< etite. 
Unfortunately the material on the mine dump has so succumbed 
to attacks of the weather that ore and gangue minerals 
sufficiently fresh for microscopic study could not be ob- 

The denosit occurs in a general region of horn- 
blende schist, probably an altered gabbro. The 2 to 5' vein 
is an inter banded layer of amphibole in gray gneiss. The 
gangue is black amphibole schist. A few hundred yards to 
the east lies a small serpentine mass that has been intruded 
o the schia . The ore is apparently in a vein con ! ng 
in strike to the schiatoaity of the rocks. The vein she- 
movement and crushing. 



■ior to the finding of the richer deposits 
of Michigan, Arizona, and Montana, Maryland ores were 
sufficiently significant to make the state of some im- 
portance as a copper producer. Very little ore was actually 
removed from the oare Hills mine prior to 1864, At this 
time the Bare Kill Mining Company started its operations. 

The machinery at that time was very crude, assays 
were unreliable, and had to he worked in a semi -rural way, 
the miners farming :r good weather grid minir 

The ore vein, having an average thickness of 5* 
and said to have yielded 11 1/2 ] at copper, had been 
developed by an incline shaft following dowi '. e dip of 

degrees to a ■ h alons: the incline of 832 feet. The 
main shaft was braced with 8" by 8" timber at frequent 

iervals by ordinary methods of bracing. Iwo other shafts 
were used for bion* Drifts were run at frequent 
intervals and the ore re From the drifts was carried 
to the main shaft where it wis dumped into small carts, 
Ihe carts ran on small tracks, about 2 feet wide, the power 
necessary to pull them out of the mines being furnished by 

The material taken from the mine was crushed and 
the copper ore removed from the gangue. The ore also 

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contained small amounts of gold 'and silver but it v 
not known at tbe time. It is an often told story that 
the slag left over, after the copper was removed, was 
used to build houses for the workers of the Baltimore 
Copper V.'orks at Csnton. IVher it became known that the 
ore contained rrold and silver, the houses were demolished 
and the valuables removed. 

Production continued until 1886, when .the 
mine was closed because 6f reasons mentioned before. 

When the stock company took over the property 
in 1900, it equipped the mine with all necessary surface 
buildinqs, boilers, an air compressor, an old-fashioned 
hoisting engine, a Cornish pump, and a crusher. 

th the introduction of the new equipment, the 
mine was operated with s nuch greater efficiency. Practi- 
cally all of the intervening ore between the drifts was 
stoped out. The material was removed from the mine in 
the same manner 93 described before, by mules pulling the 
carts out. Other shafts, much smaller, were sunken in the 
same vicinity but no trace of these could be found. 

The Cornish pump was used to unwater the mines, 
ill of the material that was mined was run through 
the crusher, the copper bearing minerals then being removed 
and the rals being dumped on the dump heap. 

This company continued just aa the bnre Hill Mining Company 
and shipped all of its copper ore to the Baltimore Copper 
V. orks. 


Al though the mining company had operated with 
much more efficiency than anyone who had previously worked 
a, th< downfall of the price of copper, and 
the end ins of the contract to supply copper sheathing for 
the heats, ended the actual operating life of the Bare 
Hills mine for all time. 

When Mr. Herbert Brown came, into possession of 
the mine in 1905, he had the intention of resuming opera- 
tions, but being unable to cope with his adversaries in 
business, he dismantled all of the mining machinery and 
sold it. 


The Bare Hills copper mine is situated on the 
summit of a ridge -immediately west of Jones Palls and 
about 1 1/2 to 2 miles north of 
Mt. Washington, in Baltimore 
County, Md, The last build- 
ing that whs actually of use 
in mining was burned to the 
ground several years ago. This 
I lding had housed the crusher, 
boiler, and steam eneine. In 
the accompanying illustration, 
the concrete foundation can 

r eadily be made out. 


Also readily noticed are the large steel stay- 
rods that were used to hold the crusher in piece. The: 
'rods were ? inches in diameter with large thread, 
end where the nuts and washers were nlaceci. This sturdy 
construction was necessary because of the consistently 

■'■■■! jarring action of the crusher. Wo remains can be 
found of the previously mentioned Cornish pump that had 
been used to unwater the well. 

The main shaft of the mine, pictured above, has 
already been filled to within a few feet of the top to rid 
the neighborhood of the danger of anyone fa 11 ins into it« 
Some of the timber reinforcing can still be noticed. 
Judging from what can still be seen of the timber, the 
shaft must have been at least 10 feet square. No remains 


of the tracks out of the shaft can be found. The ventilat- 
ing shafts were: also- completely obliterated. 

The picture shown above is that of the mine 
dump where the gangue mineral was thrown after passing 
through the crusher to remove the ore. Due to not know- 
ing the depth of the dump, an estimation of the amount 
of waste could not be ascertained. Judging from the 
size of the predominating lumps of the gangue, the crusher 
must have done a fairly good job. 

The office used by the company when operating 
from 1900 to 1902 is shown on the following page. When 
used by the company it was a one room structure, the size 
being 15 feet square. Since then, however, there have been 
two additions to the building. 'j,he concrete floor, on which 
the safe stood, is still in the same condition as it was 

originally. No records of any business transactions 


could be found, the records of the old company having 
been destroyed in the Baltimore fire, and the records of 
the new company were not preserved. 

The office, crushing shack, and main shaft 
of the mine are all very close to each other, the remains 
of the sh*-ick being 50 feet away from the shaft and the 
office being 50 feet further 
ty in the same general dir- 
ection. The mine dump is lo- 
cated ris;ht next to the shaft. 
The only disadvantage in loca- 
tion was that the Baltimore 
Copper Works, which removed the 
metal from the ore, was located 
at Canton, approximately 15 
mllos away from the m3ne. 

Wh1 le the work of 
the mine itself was insignifi- 
cant as compared with that of 
the Western mines of today, it 

doubtless represented, in its day, no mean engineering and 
financiering ability. 



Since all of the mine records vere destroyed, 
credit for all of the information Is due the following 
men and authors of the publications: 
Keyser, R. B. - Copper. In Maryland, Its Resources, 

Industries and Institutions, pp. 114, 135, 189.% 
Weed, W. H. - The Copper Mines of the World, 

pp. 268, 1908. 
Overbeck, R. M. - Copper Ores of Maryland. 
Maryland Geological Survey, Vol. I, pp. 226, 1897. 
Weed, W. H. - Copper Deposits of the Appalachian States, 

. pp. 64, 65, 1911. 
Professor Joseph T. Singeweld, Jr. 
Mr. Donald Coale. 

Dr. J. J. Rut ledge, Chief Engineer, Bureau of Mines. 
Photographs and description by author.