MINING PRACTICE. 2^ 



■working faces or stopes is made the subject of a separate contract, 

 the muckers being paid per foot sunk or driven, or per cubic 

 fathom stoped, or per skip hoisted. 



Pumping. — Beyond the water produced by seapage from the 

 surface, which is a variable quantity according to the season of the 

 year, there is no great amount of water to contend with, especially 

 in the lower levels of the mines. Occasionally, however, an unex- 

 pectedly large influx of water is met with during development, 

 caused no doubt by the intersection of a cross-course or dyke form- 

 ing a natural water-channel. Such an outburst occurred in January 

 1898 in the Nundydroog Mine, the flow of water during the first few 

 days being estimated at 30,000 gallons per hour, resulting in the 

 temporary flooding of the mine. 



The system of drainage in vogue is common to all mines. The 

 most conveniently situated shafts are provided with pit-work and 

 the water is brought to them along channels cut in the levels and 

 cross-cuts. There it is collected in cisterns and elevated to the 

 surface by Cornish pumps. In the bottom stage the water is usually 

 elevated by a bucket-lift, afterwards by plunger-lifts. The diameter 

 of the plunger-lifts varies usually from 6 to 14 inches. In the new 

 vertical shaft at Champion Reef to which the drainage of the mine 

 has been concentrated, the water is brought to the surface in 10-inch 

 plunger-lifts in stages of 400 feet. At Nundydroog a Cornish pump 

 with 14-inch rams has been put in to cope with the increased 

 supply of water from the outburst referred to. The pump spears 

 are usually made of teak-wood or pitch-pine rods 7 to 12 inches 

 square, in lengths of about 30 feet, connected by wrought iron 

 strapping plates. 



When water is met with during shaft or winze-sinking, it is either 

 baled by hand from the sump into the buckets, kibbles or skips, or 

 it is dealt with by Cameron or Evans pumps worked by compressed 

 air. Worthington pumps actuated by compressed air are also 

 employed. They are usually fixed for permanent work in those 

 places where it is impossible or inconvenient to extend the Cornish 



