MINING PRACTICE. 



29 



month. Sunk at company's expense, by machine drills, actuated by 

 compressed air. No pumping has been necessary. The following is 

 the average cost per foot : — 





Shillings. 



Per cent. 



Labour .... 



128-16 



32-3 



Timber , . 



, . 32*00 



8*2 {a) 



Explosives and general stores 



54*94 



13-8 



Compressed air for three drills 



134*6 



339 



Hoisting deads , 



44 8 



113 



Drill sharpening . 



20 



•5 





396-5 



IOO'OO 



or Xlc/8 per foot. 

 (a) The timber item is low on account of the small size of the shaft and 

 the use of cheap Irul timber. 



2. Oakley's shaft. — A new vertical shaft sunk in the Ooregum 

 Mine at company's expense. Dimensions, within timbers, 16x8 feet 

 (see PI. 3). Depth to the end of June 1900, 437 1 feet. Average rate 

 of progress 25 feet per month, the greatest amount sunk in one month 

 being 33 feet. The cost per foot during 18 months' work averaged 

 ^24*8, The following is the percentage ratio of the main items of 

 cost approximately : (b) 



Labour ..... 



Timber ..... 



Compressed air for three drills 

 ditto for pump 



Explosives .... 



General stores . . . 



Hoisting deads . . . 



27 



per cent 



21 





17 



» 



II 



5» 



IO 



»1 



IO 



n 



4 



tt 



(b) Only an approximation could be obtained, as in the accounts kept the 

 cost of running a main cross-cut was included. 



3. The new Vertical shaft at the Champion Reef Mine. — Sunk at 

 company's expense. Dimensions, within timbers, 16x8 feet (see 

 PI. 2). Depth at the end of July 1900, 1,112 feet. Rate of progress 

 averaged 28 feet per month, and cost per foot £29-9. 



4. Edgar's shaft, Mysore Mine. — Sunk at company's expense. 

 Size of excavation, 20 feet. Diameter within the brick walling, 18 feet. 

 Depth at the end of May was 409 feet. Average speed of sinking, 20 



