IRON INDUSTRY IN THE UNITED STATES 107 



The first inventions which made plentiful the iron in- 

 dispensal)le for all our material civilization were Cort's pro- 

 cesses for puddling and rolling. In the decade 18G0-70 the 

 process devised by Sir Henry Bessemer, to which his name 

 attaches, began a revolution in the iron trade. Bessemer 

 steel to-day has displaced puddled iron in most of its uses. 

 Not only this, the cheap and abundant supply, besides filling 

 needs previously existing, has opened vistas for new plant, 

 machinery, durable instruments of production of all sorts. 



But the Bessemer process depends for its availability 

 on special kinds of ore and pig iron — such as are well nigh 

 free from sulphur and especially from phosphorus. But 

 the greater part of the eastern ores were too highly charged 

 with phosphorus, or for other reasons unavailable. The 

 Lake Superior iron region, long known to explorers and geol- 

 ogists, suddenly sprang into commanding place. Here were 

 abundant and superabundant supplies of rich and properly 

 constituted ore. These and the equally abundant coal of 

 Pennsylvania were brought together, the iron made from 

 them was converted into steel by the Bessemer process; and 

 thus only became possible the astounding growth in the pro- 

 duction of iron and steel in the United States. 



The iron mines of the Lake Superior region stretch in 

 widely separated fields along the lake, from the middle of 

 its southern shore to its extreme northwestern end. In all 

 these fields the ore has been secured by what we commonly 

 think of as mining, — by digging into the bowels of the earth, 

 and bringing the material up from a greater or less depth. 

 But m very recent years the latest and now the most important 

 of the fields has given opportunity for the simplest and cheap- 

 est form of mining : great bodies of ore are lying close under 

 the ground, and, when once the surface glacial drift has been 

 removed, obtainable by simply digging and shoveUing, as 

 from a clay pit. 



From the shipping port the ore is carried eastward by 

 water to meet the coal, — the coal being coked at the mmes, 

 and in that form made best available for smelting purposes. 

 Some of the ore goes down Lake Michigan to Chicago, where 

 it meets the coal from Pennsylvania about half way. Some 



