sales of copper ores during the three years the mines were actively worked amounted to over $40,500; but the product was not sufficient to meet the expenditures.

1836, in Bristol, Conn. It was vigorously-extensive mining operations have been worked from 1847 to 1857, and produced carried on; a shaft upon the latter having larger amounts of rich vitreous and pyritous reached in 1853 the depth of 396 feet. The ores than have been obtained from any other mine in the United States. No expense was spared in prosecuting the mining, and in furnishing efficient machinery for dressing the ores. Although 1800 tons of ore, producing over $200,000, were sent to market, the ore yielding from 18 to 50 per cent. of copper, the mine proved a losing affair, and was finally abandoned in 1857.

The mines in Frederick county, Maryland, in the neighborhood of Liberty, were near the red sandstone formation, though included in argillaceous and talcose slates. A number of them have been worked at different times up to the year 1853, when they were finally given up as unprofitable.

and the mine was reported as improving. The ore sent to the smelting works at Baltimore, in December of that year, yielded 16.03 per cent. of copper. Within seven miles of Baltimore the Bare Hill mine has produced considerable copper, associated with the chromic iron of that region.

The New Jersey mines have all failed. from insufficient supply of the ores. The Schuyler mine, at Belleville, produced rich A more newly discovered and richer copvitreous copper and chrysocolla, disseminated per district in Maryland is near Sykesville, through a stratum of light brown sandstone, on the Baltimore and Ohio railroad, 32 miles of 20 to 30 feet in thickness, and dipping at from Baltimore, in a region of micaceous, an angle of 12°. During the periods of its talcose, and chloritic slates. A large bed of being worked in the last century, the exca- specular iron ore lying between the slates vations reached the depth of 200 feet, and was found to contain, at some depth below were carried to great distances on the course the surface, carbonates and silicates of copof the metalliferous stratum. The mine was per, and still further down copper pyrites. then so highly valued that an offer of £500,- In the twelve months preceding April 1, 000, made for it by an English company, was 1857, 300 tons had been mined and sent to refused by the proprietor, Mr. Schuyler. In market, the value of which was $17,896.92, 1857-58 attempts were made by a New York company to work the mine again, but the enterprise soon failed. Among the other mines which have been worked to considerable extent in New Jersey are the Flemington mine, which resembled in the character of its ore the Schuyler mine, and the Bridgewater mine, near Somerville, at which Like the last two named, all the other lonative copper in some quantity was found in calities of copper ores of any importance the last century; two pieces met with in 1754 along the Appalachian chain and east of it weighing together, it was reported, 1,900 lbs. are remote from the range of the red sandA mine near New Brunswick also furnished stone, and belong to older rock formations. many lumps of native copper, and thin sheets In the granites of New Hampshire, pyritous of the metal were found included in the sand- copper has been found in many places, but has stone. At different times this mine has been nowhere been mined to any extent. In Verthoroughly explored, to the loss of those en-mont, mining operations were carried on for gaged in the enterprise. In Somerset county, several years upon a large lode of pyritous the Franklin mine, near Griggstown, has been copper, which was traced several miles worked to the depth of 100 feet. Carbonate through Vershire and Corinth. At Strafand red oxide of copper were found in the ford, pyritous ores were worked in 1829 and shales near the trap, but not in quantity suf- afterward, both for copperas and copper. In ficient to pay expenses. In Pennsylvania, New York, excellent pyritous ores were pronear the Schuylkill river, in Montgomery and duced at the Ulster lead mine in 1853. Chester counties, many mines have been Among other sales of similar qualities of ore, worked for copper and lead at the junction one lot of 50 tons produced 24.3 per cent. of of the red sandstone and gneiss. Those veins included wholly in the shales of the red sandstone group were found to produce copper chiefly, while those in the gneiss were productive in lead ores. At the Perkiomen and Ecton mines-both upon the same lode

copper.

In Virginia, rich ores of red oxide of copper, associated with native copper and pyritous copper, are found in the metamorphic slates at Manasses Gap, and also in many other places further south along the Blue

copper. This is metallic copper, precipitated from the waters of the mine by means of scrap iron thrown into the vats in which these waters are collected. The iron being taken up by the acids which hold the copper in solution, the latter is set free, and deposited in fine metallic powder. The ore is smelted in furnaces constructed on the German plan, and being put through twice, produce a regulus of 55 per cent. As soon as the proper furnaces and refineries can be constructed, it is intended to make ingot copper, and by working more of the mines belonging to the company it is expected the monthly production will soon be raised to 2,000 tons of 10 to 12 per cent. ore.

crease in the supply of the metal will be derived from this source.

The existence of native copper on the shores of Lake Superior, is noticed in the reports of the Jesuit missionaries of 1659 and 1666. Pieces of the metal 10 to 20 lbs. in weight were seen, which it is said the Indians reverenced as sacred; similar reports were brought by Father Dablou in 1670, and by Charlevoix in 1744. An attempt was made in 1771 by an Englishman, named Alexander Henry, to open a mine near the forks of the Ontonagon, on the bank of the river, where a large mass of the metal lay exposed. He had visited the region in 1763, and returned with a party prepared for more The two other companies have erected ex- thoroughly exploring its resources. They, tensive smelting works; and the mines of however, found no more copper besides the the Burra Burra are producing 450 to 500 loose mass, which they were unable to retons per month of 14 per cent. ore, and move. They then went over to the north those of the Polk County Company about shore of the lake, but met with no better 300 tons of 15 per cent. ore. Both com- success there. General Cass and Mr. H. R. panies will soon be able to make ingot cop- Schoolcraft visited the region in 1819, and per. The report of the Union Consolidated reported on the great mass upon the OntonCompany for the first year of their opera- agon. Major Long, also, in 1823, bore wittions presents, against expenditures amount-ness to the occurrence of the metal along ing to $307,182.77, receipts of $457,803.73, the shores of the lake. The country, till leaving a profit of $150,620.96. A large the ratification of the treaty with the Chipportion of the regulus is shipped to England for sale.

The profits of these mines were greatly reduced the first few years of their operation by the necessity of transporting the ores 40 miles to a railroad, and thence more than 1,000 miles by land and water to the northern smelting works. The establishment of furnaces at the mines not only reduces this source of loss, but renders the great body of poorer ores available, which they were not before. A railroad is now in process of construction to connect the mines with the Georgia railroads.

pewa Indians in 1842, was scarcely ever visited except by hunters and fur-traders, and was only accessible by a tedious voyage in canoes from Mackinaw. The fur companies discouraged, and could exclude from the territory, all explorers not going there under their auspices. Dr. Douglass Houghton, the state geologist of Michigan, in the territory of which these Indian lands were included, made the first scientific examination of the country in 1841, and his reports first drew public attention to its great resources in copper. His explorations were continued both under the state and general government until they were suddenly terminated with his life by the unfortunate swamping of his boat in the lake, near Eagle river, October 13, 1845.

West of the Alleghanies, the only copper mines, besides those of Lake Superior, are in the lead region of Wisconsin, Iowa, and Missouri. A considerable number of them have been worked to limited extent, and In 1844 adventurers from the eastern states small blast furnaces have been in operation began to pour into the country, and mining smelting the ores. These were found only operations were commenced at various places near the surface, in the crevices that con- near the shore, on Keweenaw Point. The tained the lead ores; and in Missouri, in companies took possession under permits horizontal beds in the limestone, along the from the general land office, in anticipation line of contact of the granite. The ores of the regular surveys, when the tracts could were mixed pyritous copper and carbonate, be properly designated for sale. Nearly always in very limited quantity. The amount one thousand tracts, of one mile square each, of copper produced has been unimportant, were selected the greater part of them at and it is not likely that any considerable in- | random, and afterward explored and aban

doned. In 1846 a geological survey of the region was authorized by Congress, which was commenced under Dr. C. T. Jackson, and completed by Messrs. Foster and Whitney in 1850. At this time many mines were in full operation, and titles to them had been acquired at the government sales.

The

and nowhere in quantities to justify the continuation of mining operations that were commenced upon them. The veins on Keweenaw Point cross the ridges nearly at right angles, penetrating almost vertically through the trap and the sandstones. Their productiveness is, for the most part, limited to certain amygdaloidal belts of the trap, which alternate with other unproductive beds of gray compact trap, and the mining explorations follow the former down their slope of 40°, more or less, toward the north. thickness of the veins is very variable, and also their richness, even in the amygdaloid. The copper is found interspersed in pieces of all sizes through the quartz vein stones and among the calcareous spar, laumonite, prehnite, and other minerals associated with the quartz. These being extracted, piles are made of the poorer sorts, in which the metal is not sufficiently clear of stone for shipment, and these are roasted by firing the wood in termixed through the heaps. By this proc

is more readily broken and removed. The lumps that will go into barrels are called "barrel work," and are packed in this way for shipment. Larger ones, called "masses," some of which are huge, irregular-shaped blocks of clean copper, are cut into pieces that can be conveniently transported, as of one to three tons weight each. This is done by means of a long chisel with a bit threefourths of an inch wide, which is held by one man and struck in turns by two others with a hammer weighing 7 or 8 lbs. A groove is thus cut across the narrowest part of the mass, turning out long chips of copper onefourth of an inch thick, and with each suc

The copper region, as indicated by Dr. Houghton, was found to be nearly limited to the range of trap hills, which are traced from the termination of Keweenaw Point toward the south-west in a belt of not more than two miles in width, gradually receding from the lake shore. The upper portion of the hills is of trap rock, lying in beds which dip toward the lake, and pass in this direction under others of sandstone, the outcrop of which is along the northern flanks of the hills. Isle Royale, near the north shore of the lake, is made up of similar formations, which dip toward the south. These rocks thus appear to form the basin in which the portion of Lake Superior lying between is held. The trap hills are traced from Kewee-ess the stone entangled among the copper naw Point in two or three parallel ridges of 500 to 1,000 feet elevation, crossing Portage lake not far from the shore of Lake Superior, and the Ontonagon river about 13 miles from its mouth. They thence reach further back into the country beyond Agogebic lake, full 120 miles from the north-eastern termination. Another group of trap hills, known as the Porcupine mountains, comes out to the lake shore some 20 miles above the mouth of the Ontonagon, and this also contains veins of copper, which have been little developed until the explorations commenced near Carp lake in these mountains in 1859. These have resulted in a shipment of over 20 tons of rough copper in 1860, and give en-ceeding cut the groove is deepened to the couragement to this proving a copper-pro- same extent until it reaches through the mass. ducing district. The formations upon Isle The process is slow and tedious, a single cut Royale, which is within the boundary of the sometimes occupying the continual labor of United States, although they are similar to three men for as many weeks, or even longthose of the south shore, and contain copper er. This work is done in great part beveins upon which explorations were vigor- fore the masses can be got out of the ously prosecuted, have not proved of impor- mine. The masses are found in working the tance, and no mines are now worked there. vein, often occupying the whole space beThe productive mines are comprised in three tween the walls of trap rock, standing updistricts along the main range of the trap on their edges, and shut in as solidly as if hills. The first is on Keweenaw Point, the all were one material. To remove one of the second about Portage lake, and the third very large masses is a work of many months. near the Ontonagon river. All the veins It is first laid bare along one side by extendare remarkable for producing native copper alone, the only ores of the metal being chiefly of vitreous copper found in a range of hills on the south side of Keweenaw Point,

ing the level or drift of the mine through the trap rock. The excavation is carried high enough to expose its upper edge and down to its lower line; but on account of ir