l\l)KX 



819 



Thresh, M., 248 

 Throw, 9 

 Tirm;iimite, 126 

 Tin, 176 



character of ore bodies, 178 



extraction of, 184 



p>< graphical distribution, 178 



geological horizon, 184 



in Alaska, 181 



in canned goods, 186 



in foreign countries, 181 



ores of, 177 



origin of ores, 177 



production of, 298 



properties of, 176 



uses of, 185 

 Titanite, 273 

 Titanium, 271 



character of ore bodies, 273 



extraction of, 274 



geographical distribution, 274 



geological horizon, 274 



ores of, 272, 273 



origin of ores, 273 



production of, 307 



properties of, 271 



uses of, 274 

 Travertine, 6 

 Troy, Vermont, 199 

 Tungsten, 269 



character of ore bodies, 270 



extraction of, 270 



geographical distribution, 270 



geological horizon, 270 



production of, 307 



properties of, 269 



uses of, 270 

 Tungstite, 269 

 Turgite, 190 

 Turquoise, 218 

 Type metal, 174 



U 



Ural Mountains, 214 

 Uraninite, 278 

 Uranium, 278 



character of ore bodies, 279 



extraction of, 280 



Uranium, geographical distribution, 

 280 



geological horizon, 280 



ores of, 279 



origin of ores, 279 



production of, 306 



properties of, 278 



uses of, 280 

 Utah, silver in, 95 



Valentinite, 171 

 Vanadium, 276 



character of ore bodies, 277 



geographical distribution, 277 



geological horizon, 277 



ores of, 276 



origin of ores, 276 



production of, 306 



properties of, 276 



uses of, 277 



Van Hise, C. R., 55, 207, 209 

 Veatch, A. C., 222 

 Veins, 11 



age of, 18 



fissure, 12 



gash, 12 



irregularities in, 15, 17 



occurrence of, 13 



parallel, 13 



ribbon structure in, 17 



richness of, 14 



segregated, 12 

 Vennillion, district, 206 

 Vogt, J. H. L., 28, 46, 191, 239 

 Voit, F. W., 240 

 Voltzite, 257 



W 



Wad, 246 

 Walker, T. L., 239 

 Waters, acidulated, 6 



carbonated, 6 



sulphur bearing, 7 



thermal, 7, 30 

 Watson, T. L., 250 

 Weed, W. H., 18, 95, 120, 150, 165 



