Januaey 6, 1911] 



SCIENCE 



of our ore supply comes from the three 

 Lake Superior states, and three out of the 

 four fifths from Minnesota alone. Ala- 

 bama, Tennessee and Georgia together 

 yield one tenth and the remaining tenth is 

 divided among a dozen or more other 

 states, of which New 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 sup- 

 ply, 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 

 <!ould be mined. Magnetites for example 

 in the lump from the Adirondacks afforded 

 •over 60 per cent, metallic iron. Specular 

 hematites from the Lake Superior districts 

 necessarily yielded 65. For some years no 

 one regarded them with respect if they con- 

 tained less. Red hematites from Alabama 

 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 fea- 

 tures. Magnetites in the Adirondacks are 

 now concentrated before shipping and in 

 instances two and one half to three tons 

 are condensed 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 

 specular 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 con- 

 cerned, which in the form of lumps, crusts, 

 pipes, etc., are distributed throughout 

 ochres and clays, the percentage of avail- 

 able 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 materials. 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 the total production 

 of pig iron, we find the yield in the large 

 way to be about 50 per cent. 



In order to gain some idea of the com- 

 parative merits of these figures when set 

 alongside the percentages in the ores pro- 

 duced in other lands, a few cases may be cited. 

 Germany in 1907 produced 27,700,000 tons 

 of ore, exported nearly four millions and 

 imported eight and one half millions. Of 

 the local production three quarters were 

 obtained from Elsass, Lothringen and Lux- 

 emburg, whose percentage in iron ranges 

 between 30 and 40 and is on the whole not 

 very different from Alabama's present per- 

 centages of 36-37. Germany's imports, of 

 course, range much above these figures, else 

 the ore could not stand the freight charges 

 from mines in such remote countries as 

 Sweden, Spain and Algiers. 



Great Britain produced in 1907, approxi- 

 mately, 15,000,000 tons, of which about 

 three quarters were the so-called impure 

 carbonates yielding 30-35 per cent. iron. 

 One ninth of the total was red hematite at 

 50-55. The general average would be 

 somewhat less than that of Alabama. Im- 



