93 
IRON. 
Case K. — Iron ores from the ranges of the Lake Superior 
region. It is the near presence of the remarkably pure and 
abundant deposits of hematite and magnetite that has enabled 
Chicago’s iron industry to attain its present importance. 
Case li, — Type specimens of iron ores. These are:~the 
black oxide, 72 per cent, iron; the red oxide, hematite, 
70 per cent, iron; the hydrous oxides, turgite, 66 per cent, iron; 
gothite, 64 per cent, iron; and limonite, 60 per cent, iron; the car- 
bonate, siderite, 48 per cent. iron. Many varieties of these ores are 
shown, which are known by the names of yellow ochre, bog ore, 
pipe ore and brown he 7 ?iatite, forms of limonite, red ochre, specu- 
lar, micaceous, needle and kidney ores, forms of hematite; 
stone, black band, and spathic ores, forms of siderite. The rest of 
this case is occupied by ores from the western states. 
Case 16. — A series of limonites from the eastern states 
that illustrate the transition from a porous, impure bog-iron ore, 
to a compact brown limonite and through gothite and turgite tQ 
hematite. 
Case 17, Front. — Iron ores, Western States. 
Case 17, Rear. — Iron ores, New South Wales. 
Case J.— Iron ores, England, France and Germany. Con- 
spicuous among the English ores are the ochres, which are mix- 
tures of limonite or hematite with clay; the soft, bright, red hema- 
tites which occur in limestone, and the compact, spathic ore of the 
coal measures. The German irons show the more fibrous hema- 
tites and limonites and the well crystallized “ sparry ” siderite. 
Case H. — Iron ores. South America. 
Case 14. — Iron ores, Russia. 
A map on the wall shows localities of the United States pro- 
ducing iron ore. Several charts show types of blast furnaces 
used in the reduction of iron. 
