95 
HALL 76. 
METALLURGY OF IRON AND STEEL. 
This Hall contains a series of the intermediate and final 
products of the iron-working industry, intended to lead the visitor 
gradually from a view of the mining of the ore to some of the 
higher products of the iron-worker’s art. 
No. 1. — Model of the Chandler iron mine, Ely, Minnesota. 
At the rear of the model two shafts descend and at levels 6o feet 
apart, horizontal galleries run from the shaft and connect at inter- 
vals with other passages. Figures of miners at work may be seen 
by looking through these cross-ways from the ends of the model. 
From the two main galleries, sloping ways, not shown in the 
model, lead upward to passages at higher levels which do not con- 
nect with the shaft. Here as the ore is excavated it is thrown 
through chutes to the tramways of the main galleries, and there 
taken by ore cars to the shafts and raised to the surface. The 
timbering is to prevent the top and sides from caving. Upon the 
wall is a large painting representing a section of the Soudan 
Mine of Tower, Minn. 
Case 2. — The extraction of iron from its ores by the blast 
furnace. The material fed to the furnace and given out by it is 
shown, also a series of pig irons showing the characteristic frac- 
tures of the different grades. 
Cases 2 and 3 JB. — Alloys of iron used in iron working. 
Cases No. 3 A and 4 A. — A collection illustrating the 
methods of testing structural iron and steel. In general a piece 
of steel is broken and the strain at which it yields is noted. Other 
pieces are bent hot and cold and their behavior in respect to 
cracking is noted. At the ends of the cases are specimens show- 
ing the successive stages of rolling an ingot into a rail or beam, 
also the method of crushing a number of bars or “///<? ” of iron 
into one solid beam. 
Case 3 C. — Fibrous fracture of wrought iron. 
Case 3 D. — “Crystalline ” fracture of wrought iron. 
Case 4 B. — Malleable cast iron. This is a cast iron the sur- 
face of which has been decarbonized and thus transformed into 
wrought iron by the action of oxide of iron at a high temperature. 
