82 WALDON FAWCETT 



the Gogebic range, partly in Michigan and partly in Wisconsin ; 

 the Vermilion and Mesabi ranges in Minnesota. 



There are as many different methods of mining in vogue 

 in the iron region as there are separate ranges, although the 

 various systems are not thus apportioned. Virtually every 

 mine on any of the four ranges other than the Mesabi is worked 

 on the overhead stoping, the caving, or the milling plan. On 

 the Mesabi range the ore is taken out by means of steam 

 shovels. The essential feature of the first mentioned plan is 

 the construction of a timber lined shaft, perhaps twenty feet 

 wide, which is sunk into the earth a distance of two thousand 

 feet or more. Opening from this shaft are tunnels, which are 

 driven horizontally through the deposit of ore, and constitute 

 corridors, along which the iron may be conveyed in cars to 

 the main shaft and thence hoisted to the surface. 



The caving method is not very different from that just 

 described. One or more shafts are sunk, and a considerable 

 portion of the deposit is honeycombed with side passages 

 through which the ore is passed to the main artery of com- 

 munication and thus to the surface. The system derives its 

 name from the fact that, as the ore is taken out, the surface 

 of the ground gradually caves in, forming an immense pit. 



The milling system can be employed most advantageously 

 where the ore deposit is located in a hill of considerable altitude. 

 A tunnel, probably twelve or fifteen feet square, is driven into 

 the base of the hill, and connecting with this are shafts sunk 

 directly through the ore from the summit of the hill. Explo- 

 sives loosen the ore surrounding the perpendicular shafts, and 

 it falls directly down these great chutes into the little cars 

 which are waiting to receive it in the tunnel below. 



The greatest measure of the romance of iron mining is 

 bound up, however, in the steam shoveling method of procur- 

 ing the ore. Open pit mining, as it is called, is not only the 

 best and cheapest of all known processes, but it constitutes 

 one of the most picturesque industrial operations to be found 

 anywhere in the world. Of course, this method of taking out 

 the ore wholesale can be employed only on the Mesabi range, 

 where great deposits occur near the surface of the earth, cov- 

 ered, as it were, by only a thin blanket of soil. The Mesabi 



