212 GEOLOGICAL SUEVEY OF THE TEERITOEIES. 



the same used in California and Ijf'evada. Ores are never sent here for 

 treatment which assay less than $60 per ton, and the average is about 

 $100 per ton. These ores are roasted with salt in a reverberatory fur- 

 nace and amalgamated in pans. They consist chiefly of silver glance, 

 zinc blende, and copper (and iron) pj^rites. They are first dried in an iron 

 pan and then crushed dry in a six-stami) mill. After this they are sub- 

 mitted to a chloridizing roasting in a reverberatory furnace with salt. The 

 pyrites oontaiued in the ore is sufficient in amount to re4ct on the cloride 

 of sodium and set free tl e chlorine without the necessity of adding sul- 

 phate of iron, which is usually done. The material is then amalga- 

 mated in iron pans and filtered through cloths, after which it is retorted, 

 assayed, melted, run into bricks, and stamped. The ore from the Whale 

 lode contains about equal values of silver and gold, and will be run into 

 bars as auriferous silver and sent East for separation. 



EMPIEE CITY. 



The principal mines in the neighborhood of Empire City are the 

 Conqueror, Silver Mountain, Tenth Legion, Empire, Livingstone, At- 

 lantic, Gold Dirt, Eosencranz|, Eupp and Cross, Tom Benton, and Star, 

 the Curtis, and Ellsworth, (the former close to Mr. Ball's mill, and the 

 latter almost in the town,) and the Bay State. Many others look favor- 

 ably, but are not mentioned, because the shafts are not yet sunk deep 

 enough to render an intelligent opinion of their capacity possible. 



The Conqueror lode. — This lode is located a mile or two above the 

 settlement of Upper Empire. The shaft is two hundred and seventy 

 feet deep, and the ore is all pyrites in a fine state of division. There 

 are, as yet, no drifts commenced, but the ore is shoveled out into buck- 

 ets and dumped out as a mass, resembling moist sandy clay, inter- 

 spersed with fine crystals of iron pyrites. The engine, which is of twen- 

 ty-two horse power, hoists out in forty seconds. They get out two cords 

 of ore, at from eight to ten tons per cord, in a day. This Conqueror ore 

 assays very well, but the data of its yield I am unable to find in my 

 notes. - 



The Eosencranz ore resembles that of the Conqueror. The crevice of 

 the Silver Mountain lode is five and one-half feet thick. It had lain 

 idle for some months previous to the date of my visit, (July,) and there 

 were ten feet of drift snow in the bottom of the shaft when I descended 

 it. The roof and walls of the mine were covered with fine crj^stals of 

 Green Vitrol. 



All these lodes were recorded as striking northeast and southwest. 



Mr. Ball assures me that the general character of the gangue rock in 

 a.11 this , district is granitic. 



There are nine amalgamation mills in this (the Union) district. 



CE^TEAL CITY. 



The Gregory lode. — This crops out near the lower end of Central 

 City, was the first discovered in Colorado, and has been worked ever 

 since with profit, in spite of the disturbances which have checked the 

 development of so many other mines. At present there are seventeen 

 shafts sunk in the lode, only three of w^hich are being worked. The first 

 class ore of this vein is an iron i)yritesin which a tolerably couvstant per- 

 centage of gold is found mechanically diffused, (or as some think chem- 

 ically combined, with sulphur,) but at all events in a state of very fine 



