150 TRANSACTIONS OF THE [APR. 21, 



A notable feature in the Norwegian Section was the exhibit of 

 the famous Kongsberg silver-mine, in which were displayed ropes 

 and wires of silver^, some over twelve inches long, varying in 

 thickness from that of a needle to more than an inch ; these 

 were interlaced, and in part attached to the rock. Even more 

 striking, however, was a perfect cube of native silver fully an 

 inch in diameter, and some groups of cubo-octahedrons, measur- 

 ing over half an inch in diameter, and covering surfaces over 

 four inches square. Plans and diagrams of the mines accom- 

 panied this series. 



Of considerable interest was a commercial exhibit of the min- 

 erals containing the rare earths, which in Norway are carefully 

 preserved by the miners of feldspar, apatite, and quartz. The 

 exhibit contained orangite, gadolinite, fergnsonite, zircon, mo- 

 lybdenite, and other minerals, to be sold by the pound. In one 

 collection were fine crystals of thorite, broggerite, zircon, gado- 

 linite, molybdenite, etc. 



The Hungarian Section contained a very interesting case of 

 opals, and also opal in the trachyte matrix, from the famous. 

 Hungarian mines at Ozernowitza, which have been worked for 

 over three hundred years. 



In the Roumanian Section was exhibited a remarkable series 

 of ambers, strikingly like those from Catania, Sicily, in form 

 and in color; the different colors shown were light yellow, dark 

 yellow, cloudy-white, opaque white, black, brown, bluish-green, 

 dark opalescent blue, opaque red. This amber was all found in 

 the department of Biizeoand in these places: Bisca-rusilei, Bisca- 

 Ohisjdului, Coltzia, Valea-boului, and Bodila. The Roumanian 

 amber is exceedingly rare, and is very highly valued in that 

 country. 



The United States exhibit of minerals was prepared by Prof. 

 William P. Blake, and was under my charge at the Exposition. 

 It was not intended to be a complete collection of American 

 minerals, but rather such a representative series as could be 

 gathered in the short time allotted to its formation. Among the 

 exhibits may be mentioned that of the famous Anaconda Mining 

 Company, containing a set of specimens forming a series of the 

 ores, concentrates, and matte of that great copper-mine. Pi'of. 

 Blake exhibited a crystal of columbite, of the size of a man's 

 hand, from the Black Hills ; the Copper Basin Mining Com- 

 pany had a fine series of malachite and azurite in the sandstone 

 conglomerate, from Copper Basin, Prescott, Yavapai County, 

 Arizona ; from Harney Peak, Black Hills, Dakota, were several 

 tons of vein rock, illustrating the occurrence of cassiterite; from 

 the New Almaden quicksilver-mines, California, a case of fine 

 specimens of cinnabar and bitumen associated with native mer- 



