Appendix. 383 



their normal depth. Hydraulic mining of the highest and most perfect 

 development is therefore possible in the Caribou district, with nothing to 

 hinder or to interrupt it except the long and severe winters, during which 

 the snowfall is measured by feet and the thermometer drops often below 

 the freezing point of mercury, and at times touches a record quite as low 

 as any Arctic explorer has experienced in the far north. 



Almost all of the pay dirt in the placer deposits of Caribou resembles 

 the material contained in the Blue leads of California.* It is a sticky, 

 compact conglomeration of highly washed gravel, sand, and clay, with 

 which every placer miner is familiar, and from which, when found, he 

 always hopes to reap that rich reward for which he is in search. In the 

 Horse Fly hydraulic mine the dirt hitherto worked has been a free 

 washing gravel, but two seasons ago it changed to a hard, compacted, 

 cemented gravel, that must be crushed before washing to win from it 

 all the gold it contains. Since this change presented itself in the face of 

 the pit only a small portion of the gold contained in the gravel piped off 

 has been recovered, chunks of the cemented gravel being found at the foot 

 of the sluices. A ten-stamp mill with a capacity to crush from 100 to 

 1 20 tons per twenty-four hours, is, I believe, about to be erected there. It 

 is estimated it will cost from idol. 50 cents to idol. 75 cents per ton to 

 mine and mill the cement, which working tests show contains from 4dols. 

 82 cents to 5dols. 56 cents per cubic yard of gold. The mill will be 

 operated during summer with water power, and during winter with steam, 

 as drifting can be carried on winter and summer alike. 



The vastness of the deep gravel deposits of the Caribou district is 

 shown in the pit of the Caribou hydraulic mine. The company controls 

 about three miles of the ancient river channel, which is loooft. wide 

 between the rims, and the bank of auriferous gravel rises from 35oft. 

 to lonft- .above the head of the sluices, while it is estimated that from Soft. 

 to looft. more pay dirt lies between the present workings and the bedrock. 

 The latter cannot be touched until the upper stratum is worked off. This 

 is the mine that yielded two seasons ago i28,ooodols. worth of gold 

 at a total cost of 85,ooodols. An early setting in of winter is said to have 

 deprived them of the means of taking out from 5O,ooodols. to yo.ooodols. 

 additional. There were four giants in operation last summer. Two more 

 giants were to have been put into operation last season. 



How puny the efforts of the hydraulic miners of Caribou of the sixties 

 were, when they worked with canvas hose and lin. nozzle pipes, compared 

 with the operations now going on in the district, is shown by the fact 



* I copy this statement from an able account in the San Francisco Chronicle. 



