f^Tf 72-*-— HI, OF OPERATION OF COPPER MIKES AT BARE HILLS NEAR BALTIMORE', MD. John A -1- lRY 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 v.as 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. -8- fcARLY HISTORY 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, E BARE HILL .MINIin COMPANY '■Lhe mines had been worked previously to 1864, but in that.ye 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. OUTFUT OF THE MINE 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- put. 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- d. 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. LATER HISTORY 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. THK GEE 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- tained. 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. -6- OPMUTIGK ■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 had. 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 mules. The material taken from the mine was crushed and the copper ore removed from the gangue. The ore also — r 7_ 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. -8- 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. 'DESCRIPTION OP Mil ME 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. -9« 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 -10- 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 -11- 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. -12- BIBLIOGHAPHY 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.