HISTORY OF THE NEW ALMADEN MINES 



185 



FIGURE 110. View of China dump area In 1874. Photograph shows that even at this early date the China dump was 

 being worked over for ore previously discarded, and from time to time since then It has been reworked. The build- 

 ing at the foot of the dump houses a boiler and steam engine, originally Intended to power a crusher but later con- 

 nected by a cable to provide hoisting and pumping for the Cora Blanca shaft. From L. E. Bullmore collection. 



The Randol shaft was not completed to its final 

 depth of 1,340 feet for 9 years; the work was ham- 

 pered by repeated floodings, inadequate pumps and 

 hoists, partial cave-ins which required retimbering, 

 and the laborious method used in sinking it. Below 

 the first 200 feet it was sunk by Cornish miners work- 

 ing with hand drills under a penthouse of very strong 

 and heavy timbers, which contained a windlass and 

 bucket used to hoist the broken rock. After gaining 

 each 100 feet of depth the penthouse was knocked 

 down and lowered to the bottom of the shaft, where 

 it was again assembled. In the first half year the 

 shaft was sunk 383 feet by this method. By the end 

 of 1872 it was down 515 feet, with connections run 

 to the Day tunnel ; a crosscut had nearly reached the 

 Victoria stope, which was being mined at that depth, 

 although the ore had to be backpacked up to the 800 

 level and trammed 2,400 feet to the portal of the Day 

 tunnel. By the end of 1874 the shaft had gotten be- 

 low the 1,100 level, where a crosscut driven westward 

 to the vein had struck so much water that the lower 

 80 feet of the shaft was flooded. The water was soon 

 pumped out, however, and only a little drifting on 

 the vein revealed an ore body 250 feet wide. This 

 wide ore body was the cause of great rejoicing, for 



686-671 O 63 



drifting on higher levels had found only small bodies 

 of ore which were quickly exhausted, and production 

 during 1874 had been the smallest since the first year 

 of recorded production, 1850. 



There followed a period of years during which the 

 other Randol ore bodies were found and mined out, 

 resulting in a nearly steady increase in production for 

 10 years and a gradual decline for the next 10 years. 

 The ore body struck on the 1100 level was followed 

 northward down the dip for about 700 feet to the 

 1600 level, and a second ore body which overlapped it 

 began near the 1400 level and pitched in the same 

 direction to the 2000 level. "Vein rock ?" (silica-carbon- 

 ate rock) was also struck in the Randol shaft in 1877 on 

 the 1200 level, and the virtually continuous North 

 Randol ore body, lying to the north and east of the 

 shaft, was followed upward nearly to the 800 level 

 and downward to the 1800 level. 



Even with an unprecedented supply of developed 

 ore, however, the mine was hard pressed to return a 

 profit, largely because of the inadequacy of the Ran- 

 dol shaft. The Scott furnace, which was continuously 

 fed and could handle fine ore, was invented at the 

 New Almaden mine in 1875. It was so efficient in ex- 

 tracting quicksilver that in spite of a lawsuit with the 



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