86 
principal ores, the bronze colored sulphide pyrrhotite, the brass 
colored sulphide, frequently in capillary forms, Millerite and the 
apple green silicate, Garnierite. 
Nickel ores from Canada, Oregon and New Granada. A chart 
near by gives the process of extraction of nickel from the Cana- 
dian pyrrhotite. As uses of the metal are shown specimens of 
plating, nickel steel alloy for armor, salts of use in the arts, etc. 
IRON. 
Case K. — Type specimens of the principal iron ores, these 
being the black, magnetic oxide, 7 uagnetitey 72 per cent, of iron; 
red oxide “specular iron,” hcmatitey 70 per cent.; brown oxide, 
“bog iron ore,” Iwionite 60 per cent.; carbonate, “spathic iron.” 
siderite, 48 per cent. 
Cases K, L, J, H • — Iron ore from various localities in the 
following order: — Washington, Colorado, Utah, Virginia, Great 
Britain, France, Germany, Spain, 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. 
MANGANESE. 
Cases 18 and 19. — Ores of manganese, chiefly the black 
oxides, pyrolusite and psilojjielane. Specimens from Colorado, 
Virginia, Brazil and Great Britain. The minerals are used for the 
liberation of chlorine for bleaching, for staining glass and pottery, 
and in the manufacture of steel. 
Case 20. — Varieties of steel, illustrating uses of iron and 
manganese. 
CENTER OF THE HALL. 
SPECIAL GROUPS AS FOLLOWS! 
M. Gossan (iron ore), from Virginia. 
N. Limonite (oxide of iron), from Virginia. 
O. Mass of copper-nickel ore, from the Evans mine, Sud- 
bury, Ontario, Canada, taken from the third level at a depth of 
