LITTLE PITTSBURGH MINE. 471 



distance of 10 feet, and was then continued 70 feet in the overlying por- 

 phyry, at every foot increasing its distance from the ore horizon. The 

 main level from this shaft running northeast also passed out of the chert 

 into the overlying porphyry, and at about forty feet from the shaft a winze 

 was started to search for the ore below; this was, however, abandoned 

 after going 15 feet, and an up-raise was started which was persistently con- 

 tinued in the overlying White Porphyry to a height of 70 feet, when the 

 Wash was reached. 



Under these circumstances it is difficult to say how thoroughly the 

 ground to the north has been prospected or whether the failure to find ore 

 bodies there is to be taken as a conclusive proof that none exists. Owing to 

 the steep dip of the formation a level was soon reached by exploring drifts, 

 at which the influx of water was too great to be handled by the pumping 

 appliances in use, and exploration became expensive and was easily discour- 

 aged when rich bodies were not readily found. 



No. 6 shaft was sunk to a depth of over two hundred feet, passing 

 through 93 feet of Wash, 75 feet of White Porphyry, and 42 feet of vein 

 material with a porphyry streak in the middle, into Parting Quartzite, and 

 then into the lower sheet of White Porphyry. Drifts to the northwest from 

 this shaft find small masses of dark crystalline limestone in the vein mate- 

 rial, similar to that found near the Daly shaft, in Little Chief ground. The 

 two northern shafts, No. 8, on Dives ground, and Winnemuck shaft No. 7, 

 had not reached the ore horizons at the time of examination, but had passed 

 through a sheet of Gray Porphyry above the White Porphyry. This is 

 probably a part of the main sheet of Gray Porphyry corresponding to that 

 in Little Stray Horse Park, which once covered the whole of Fryer Hill, 

 but has since been removed by erosion. 



Beyond the limits of the Little Pittsburgh claim the Four Per Cent, 

 shaft reached the ore horizon at a depth of about one hundred and sixty- 

 five feet, finding vein material, but, so far as known, no considerable bodies 

 of ore. 



Amie mine. The Amie claim is very nearly parallel and next east to the 

 Little Pittsburgh, and the rich northern ore body of the latter, as well as 

 the porphyry dike, can be traced continuously from one into the other. 



