KEMl', GEOLOGY AXD ECONOMICS 36? 



coal-prodiicing states of Pennsj^vania and Ohio, the iron-ore-producing 

 states of Michigan, Wisconsin and later Minnesota, came rapidly into 

 prominence. In somewhat slower growth, Alabama, during the seventies 

 and eighties, gathered headway. At present four fifths of our ore supply 

 (iomes from the three Lake Superior states and three out of the four fifths 

 from Minnesota alone. Alabama, Tennessee and Georgia together yield 

 one tenth, and the remaining one tenth is divided among a dozen or more 

 other states, of which ^sTew York is the leader. Since 1880, the total has 

 increased about sevenfold, and Pennsylvania, then the source of about 

 one quarter the supply, now yields approximately one and one half per 

 cent. Minnesota, now the great source of ore, only entered the lists in 

 1884 and only began to utilize its present great mines about ten years 

 later. 



Thus, in the brief course of thirty years, there have been very great 

 rearrangements, not only in geographical sources of supply, but still more 

 in actual amount of output. In normal, prosperous years, the annual 

 production is somewhat more than fifty million tons of ore. 



But there have also been other changes not less striking. In early days 

 and in remote situations, only the richest ores could be mined. Mag- 

 netites for example in the lump from the Adirondacks afforded over 60 

 per cent, metallic iron. Specular hematites from the Lake Superior dis- 

 tricts necessarily yielded 65. For some years, no one regarded them with 

 respect if they contained less. Red hematites from x\labama afforded 

 forty-five to fifty. The minor ores near the furnaces were often much 

 lower — but they may be passed over for the moment in emphasizing the 

 larger features. Magnetites in the Adirondacks are now concentrated 

 before shipping, and in instances two and one half to three tons are con- 

 densed to one of 65 per cent, tenure. The crude ore carries 33-35 per 

 cent. During the early years of the present decade, the general average 

 yield of Lake Superior shipments fell off about one per cent, per year — 

 so that now the soft ores, so called in contrast with the hard lump spec- 

 ular of earlier days, range somewhat above 50 per cent. Alabama ores, 

 once 45 to 50, now are very uniform at 36 to 37. So far as the brown 

 hematites are concerned, which in the form of lumps, crusts, pipes, etc., 

 are distributed throughout ochres and clays, the percentage of available 

 iron in the crude ore is lowest of all. We wash from eight to ten tons of 

 crude in order to get one ton of concentrates of say 40-45 per cent, in 

 iron, and under favorable circumstances may treat much lower raw mate- 

 rials. Soft magnetites in Pennsylvania, which on the richer outcrops 

 gave 45 to 50 per cent., are now dug in very large amounts with a yield 

 of 43. If we take the total production of ore in the United States and 



