76 MINES 



powerful mass of pyrites, which in a great many points is almost entirely iron pyrites, 

 but in others, particularly near the circumference, includes a greater or less portion of 

 copper. This mass is enveloped in talcose or hornblende rocks. More to the west, 

 there are three other masses almost contiguous to each other, which seem to bend in an 

 arc of a circle around the principal mass. They are explored as well as the last. This 

 \v;is at first worked in the open ir ; but imprudent operations having caused the walls 

 to crumble and fall in, since 1647 the excavation presents near the surface nothing but 

 frightful precipices. The workings are now prosecuted by shafts and galleries into the 

 lower part of the deposit, and have arrived at a depth of 194 fannars (nearly 430 yards). 

 They display excavations spacious enough to admit the employment of horses, and 

 the establishment of forges for repairing the miners' tools. It is asserted that the 

 exploration of this mine goes back to a period anterior to the Christian era. During 

 its greatest prosperity, it is said to have produced 1 1 millions of pounds avoird. of cop- 

 per per annum, or about 5,000 tons. It furnishes now about the seventh part of that 

 quantity ; yielding at the same time about 70,000 Ibs. of lead, with 50 marcs of silver, 

 and 3 or 4 of gold. The ores smelted at Falun produce from 2 to 2i of copper per 

 cent. But the extraction of the metal is not the sole process ; sulphur is also saved ; 

 and with it, or the pyrites itself, sulphuric acid and other chemical products are 

 made. Bound Falun, within the space of a league, 70 furnaces or factories of dif- 

 ferent kinds may be seen. The black copper obtained at Falun is converted into rose 

 copper, in the refining hearths of the small town of Ofwostad. 



In the copper mine of Garpenbergr, situated 18 leagues from Falun, there occur 14 

 masses of ore quite vertical, and parallel to each other, and to the beds of mica-slate 

 or talc-slate, amid which they stand. This mine has been worked for more than six 

 hundred years. 



The mine of Nyakopparberg, in Nericia, 20 leagues W. of Stockholm, presents masses 

 of ores parallel to each other, the form and arrangement of which are very singular. 

 It is worked by open quarrying, and with the aid of fire. 



We may notice also the copper mines of Atvidaberg, in Ostrogothia, which furnish 

 annually about a sixth part of the whole copper of Sweden. 



There are several other copper mines in Sweden. Their whole number is ten ; but 

 it was formerly more considerable. They yield at the present day in all, about 2,000 

 tons of metallic copper. 



The number of the silver mines of Sweden has in like manner diminished. In 17G", 

 only 3 were reckoned under exploration, viz. that of Hellefors, in the province of Werme- 

 land ; that of Segersfors. in Nericia ; and that of Sala or Sahllxxrg, in Westmannia, 

 about 23 leagues N.W. of Stockholm. The last is the only one of any importance. 

 It is very ancient, and passes for having been formerly very productive ; though at pre- 

 sent it yields only from 4 to 5,000 marcs of silver per annum. Lead very rich in silver 

 is its principal product. It is explored to a depth of more than 200 yards. The 

 soundness of the rock has allowed of vast excavations being made in it, and of even the 

 galleries having great dimensions ; so that in the interior of the workings there are 

 winding machines, and carriages drawn by horses for the transport of the ores. 

 At Sala, there are deposits of sulphuret of antimony. 



For the last 30 or 40 years, mines of cobalt have been opened in Sweden, principally 

 at Tunaberg and Los, near Nykoping, and at Otward in Ostrogothia. The first are 

 worked upon veins of little power, which become thicker and thinner successively ; 

 whence they have been called bead-veins. It appears that the products of these mines, 

 though of good quality, are inconsiderable in quantity. 



Lastly, there is a gold mine in Sweden ; it is situated at Adelfors, in the parish of 

 Alsfeda, and province of Smoland. It has been under exploration since 1 737, on veins 

 of auriferous iron pyrites, which traverse schistose rocks ; presenting but a few inches 

 of ore. It formerly yielded from 30 to 40 marcs of gold per annum, but for the List 

 few years it has furnished only from 3 to 4. 



The south of Finland and the bordering parts of Russia contain some mines, but 

 they are far from having any such importance as those of Sweden. 



At Orfjerwy near Helsingfors, a mine of copper occurs whose gangue is carbonate 

 of lime, employed as a limestone. 



Near Cerdopol, a town situated at the N.W. extremity of the Ladoga Lake, veins 

 of copper pyrites were formerly mined. 



Under the reign of Peter the Great, an auriferous vein was discovered in the granitic 

 mountains which border the eastern bank of the Lake Ladoga, near Olonetz. It was 

 rich only near the surface ; and its working was soon abandoned. 



Latterly, an attempt has been made to mine copper and iron ores near Eno, above 

 and to the N.W. of Cerdopol, but with little success. 



Some time ago, rich ores of iron, lying in veins, were worked near the Lake Shuyna, 

 N.W. from Cerdopol; but this mine has also been relinquished. 



