456 



METALS. 



caused a rapid advance to twenty-five, (Decem- 

 ber,) and American copper was actually re- 

 shipped from Havre to New York. 



Since the tariff of August last, importations 

 from Chili, the main source of the supply of 

 copper from abroad, have gradually declined, 

 and such is the derangement of foreign com- 

 merce, that the supplies from that country 

 must be comparatively small for many months 

 hence. From all these premises there will be a 

 short supply, unless considerable lots can be 

 returned from abroad free of duty till the open- 

 ing of navigation in May, 1862. 



Looking back upon the past year as the most 

 disastrous financially, since 1837, those interest- 

 ed in the mines of Lake Superior may congratu- 

 late themselves that but few of the adventures 

 have been suspended, that but few calls have 

 been made upon the shareholders, and that 

 nearly all the mines now in progress are earn- 

 ing dividends, or, at least, are self-sustaining. 

 A careful inspection of the published reports of 

 the principal companies shows that the cost of 

 production, including every item down to the 

 charges of the commission merchants, need not 

 exceed thirteen and a half cents per pound at 

 the richer mines, nor more than eighteen, or, 

 possibly, nineteen cents, at the poorer mines. 

 Yet the business of mining at Lake Superior is 

 but in its infancy. The same energy which has 

 developed successfully the lead, iron, coal, sil- 

 ver, and gold of the United States, will yet 

 solve, with a similar measure of success, the 

 problem of mining for copper in the richest 

 and most extensive deposits of that metal yet 

 discovered in the world. 



The statistics, down to the end of the year 

 1861, are presented in the following tables : 



The production of the several mines for the 

 last three years in rough copper, as shipped, 

 was as follows, the weights of the barrels being 

 deducted, and the results given in tons of 2,000 

 Ibs. and tenths : 



The annual shipments of rough copper, ac- 

 cording to the official statements made to the 

 Michigan Legislature, have been as follows : 



1845, Ibs 1,800 



lS46,tons 29 



1847, " 239 



1848, " 516 



1849, " 753 



1850, " 640 



1851, " 872 



1852, " 887 



1853, tons. 1,458 



1854, u 2,800 



1855, " 3,196 



1856, 5,726 



1857, u 5,759 



1858, u 5,896 



1859, " 7,245 



1860, " 9,200 



Copper in the puddling furnace. In the 

 " American Journal of Science," for Jan. 1861, 

 is an abstract of a paper by Dr. C. List, on the 

 effect of copper in the puddling furnace. It is 

 generally believed by German iron masters that 

 pig-iron containing copper cannot be puddled, 

 it having even been asserted that when one 

 puddler wishes to annoy another, he will some- 

 times throw a bit of copper (a small coin, for 

 example) into the furnace, so that the iron can- 

 not be made to " rise." "Without fully credit- 

 ing this opinion, Dr. List mentions two cases 

 observed by him tending to confirm it. In one 

 case 400 Ibs. of pig-metal placed in the furnace 

 melted in half-an-hour, at which time a sample 

 taken out was perfectly white, but the usual 

 evolution of carbonic oxide and swelling up, or 

 " rising," of the mass of scales about the iron 

 did not ensue ; and by the time the balling to- 

 gether of the iron should have commenced, it 

 became evident that the charge could not be 

 worked off. It was therefore removed, after 

 remaining about three-quarters of an hour, and 

 in flowing out, emitted numerous beautiful blue 

 sparks, which were also produced by stirring 

 the metal in the furnace, and were regarded 



