GOLD MINING IN COLOEADO. 519 



The course of the Gregory crevice is about north 45'^ east ; that of the 

 Briggs north 55° east, true. Both branches dip slightly to the southeast. 

 Near the surface the two branches are said to have been worked as one vein, 

 but being now entirely filled with old stulls and waste-rock, no opportunity is 

 afforded for studying their relations to each other. At the depth of 100 feet 

 or thereabouts they are worked separately from the point where they diverge, 

 leaving the tongue or wedge of barren country-rock standing between them. 



The Gregory crevice is worked to a depth of 130 feet for the whole 

 length of the property, and below that has been found rather unpromising, 

 while the Briggs, on the eastern part of the ground, has been worked to the 

 depth of more than 400 feet and found very productive. 



The Briggs Company have a large mill, containing 50 stamps, located on 

 the mine between their two shafts, so that the ore is delivered for treatment 

 with the least possible expense for handling. The power for driving the mill 

 is also applied to the hoisting and the other necessary work of the mine, and is 

 furnished by a steam-engine of 22J inches diameter of cylinder. Steam is 

 supplied by two tubular boilers. The hoisting power is communicated by 

 belting to the winding apparatus, which is, in most respects, similar to that 

 already described. 



This mine is said to have been one of the most productive and profitable 

 of any in Colorado. It has, however, suffered some embarrassments, and in the 

 summer of 1868 had, after a period of idleness, resumed operations under dif- 

 ferent owners. The production had therefore been suspended, the mill being 

 worked on custom ore. Since that time it is reported as having been worked 

 very successfully. 



The average value of the first-class ore produced by this mine appears 

 from 136 tons sold, during the first half of 1869, at the Smelting Works, con- 

 taining 5^ ounces of fine gold and lOJ ounces fine silver to the ton. During 

 seven months of 1869 the product of the milling rock of this mine was about 

 $55,000. The total product, including smelting ore, was $70,000 currency, 

 or about $10,000 per month. The mine is reported to be steadily improving 

 in productiveness and profitable operation. 



Sinitli and Parmelee. — The Smith and Parmelee Gold Mining Company 

 own and work the next adjoining mine on the east, claiming 300 feet on the 



