1897.] NATURAL SCIENCES OF PHILADELPHIA. 439 



part of the belt of sufficiently disintegrated rock which allows the 

 extraction of ore by the simplest processes (crushing and amalga- 

 mation) has alone been exploited. To separate the chalcedonies the 

 " stossberd " and Frue vanner are used. The most important opera- 

 tions are those of the Mitrofanovsky shaft (40 m.), Woskressensky 

 (80 m.), the shafts Gavriilo-Arkhanguelsky (70 m.), Loukochinsky 

 (73 ^ in.), Woskressensky (56 m.), Pavlovsky (50 m.), Alexan- 

 drovsky (63 m.), etc. 



In latter years the yield of gold from the primitive rocks, where 

 it occurs as an ore, has been 1300 to 1425 kilogr. per year for the 

 district of Kotchkar, while the placers have given but 300-350 

 kgr. The total production of gold from 1844 to 1897 in this region 

 is about 47,067 kgr. (103,547.4 lbs.=51.77 tons) of which 25,160 

 kgr. came from the placers, and 21,900 from the veins (since 1868). 

 To this some 450 kgr. of silver must be added. 



Amphibolic and biotitic gneisses crop out over the entire space 

 which stretches to the Lake Tschebarkoul, and beyond veins of the 

 amazonite granite disappear imperceptibly, but the ordinary our- 

 alian granite with Biotite grows more frequent and extensive 

 until it becomes predominant. The gneiss squeezed between masses 

 of granite contains frequent injections of it and innumerable dykes 

 and veins. Beyond Tschebarkoul the outcrops become more rare. 

 At 4J kilom. from the station siliceous schists appear, interrupted by 

 a serpentine; further on, chloritic, talcose and argillitic schists suc- 

 ceed. These schists are replaced by green-stones, augitic and 

 ouralitic porphyrites and aphanites, transformed here and there by 

 dynamo-metamorphic action into uralitic schists. Here and there 

 along the line of the railway gold is exploited in placers and veins. 



On August 2 (14) the party moved along the line of the trans- 

 Siberian railway to Tcheliabinsk, the easternmost point which was 

 reached during our sojourn in Russia, viz., over 30° east longitude 

 from St. Petersburg, or about 61° E. of Greenwich. This very im- 

 portant railway center is a new town built on a number of gold veins 

 which have been exploited in latter years. The mines are mostly 

 from 16 to 20 kilom. southwest of the town, and have a general 

 similarity to those of Kotchkar. One of the best organized mines 

 is St. Michael Arkhanguel, belonging to M. Wonliarliarsky & Co. 



Along the line of the railway towards Kytchtym the granite 

 is followed for 8 kilom., and near the crossing of the Miass is cut by 

 ramified veins of quartziferous diorite. The granite underlies red 



