554 



MINING INDUSTEY. 



thousandths; and the coin vahie, per ounce, of the crude bullion and of the 

 melted bar. 



statement from the records of Mefsrs. Warren Hussey &= Company, bankers at Central City, Colorado. 



Date. 



Description. 





p 











a 



Fineness of bar in- 



Coin value 

 of 



per ounce 



Where lium. 



















 I-) 



Gold. 



SUver. 



Crude 

 bullion. 



Bar. 



October, 1867 . 



Mill retort 



Briggslode 



2-15 



808K 



172 



16.48 



16.85 



January, 1868 . 



Mill retort . 



Briggs lode 













2.71 



803K 



186 



16.31 



16.76 





Mill retort . 



Briggs lode 













2.95 



811K 



180 



16.42 



16.92 





Mill retort . 



Briggs lode 













3-S6 



816 



178 



16.40 



17.01 



December, 1867 



Mill retort . 



Bobtail mine 













5.26 



863K 



128 



17.00 



17.92 





Mill retort . 



Bobtail mine 













3.00 



849K 



140 



17.27 



17.6s 





Mill retort . 



Bobtail mine 













11.03 



864K 



127 



15.96 



17.94 





Mill retort . 



Bobtail mine 













1.46 



860K 



133 



17.61 



17.87 



January, 1868 . 



Mill retort . 



Bobtail mine 













4-55 



866% 



125 



17.16 



17.98 





Mill retort . 



Bobtail mine 













1-35 



866>^ 



128 



17-74 



17.98 





Mill retort . 



Bobtail mine 













1. 16 



869 



126 



17.82 



18.03 





Mill retort . 



Bobtail mine 













3-15 



865 



125 



17-38 



17-95 





Mill retort . 



Bobtail mine 













4.85 



866 



124 



17. II 



17.98 



August, 1868 . 



Mill retort . 



Bates lode . 













8.72 



746 



241 



14.29 



15.66 



June, 1868 . . 



Mill retort . 



Bates-Hunter 













13.10 



845 



150 



15.27 



17.26 



May, 1868 . . 



Mill retort . 



Burroughs lode 











2.63 



833K 



158 



16.93 



17-39 





Mill retort . 



Burroughs lode 











3-" 



820 



166 



16.58 



17.11 



March, 1868 



Mill retort . 



Illinois lode 











4.19 



781K 



211 



15.96 



16.34 



December, 1867 



Mill retort . 



Alps lode . . 











1-73 



758K 



225 



15.61 



15.89 



June, 1868 . . 



Mill retort . 



Flack . . . 











4-43 



641 



348 



13-03 



13.66 





Mill retort . 



Flack . . . 











5.20 



653K 



330 



13.18 



13.89 





Mill retort . 



California lode 











12.42 



72i>^ 



269 



13.26 



15-14 





Mill retort . 



California lode 











7.20 



717 



267 



14.01 



15.09 



December, 1867 



Mill retort . 



Tenth Legion, (Empire) 







20.24 



886 



90 



14.65 



18.33 





Mill retort . 



Roland, (Ernpire) 







8.03 



895 



78 



17.10 



18.50 



June, 1868 . . 



Mill retort . 



Conqueror, (Empire) 







2.87 



899 



86 



18.09 



18.63 



Capacity. — The low speed at which the stamps are generally run affords 

 a much smaller working capacity than is common in Nevada and California. 

 The average duty per stamp per day in Colorado, so far as it can be ascer- 

 tained, is probably less than one tpn of rock. In the Black Hawk mill, con- 

 taining 60 stamps, weighing 850 pounds each, falling 14 inches, 15 times per 

 minute, the average duty is said to be 27 cords per week, or about 30 tons 

 per day, equal to half a ton per head. In other mills, with lighter stamps 

 and greater speed, this duty is increased considerably, but only in few mills 

 amounts to a ton per day. It is said by some that more gold is obtained by 

 slow speed than by high ; and it is quite probable that the difference in the 



