SURFACE EQUIPMENT. 43 



WATER-SUPPLY AND STORAGE. 



For the water required for milling and steam-generation, the 

 mines are dependent on surface drainage during heavy rainfall and 

 on the water pumped from the mines and from special water- 

 shafts sunk for that purpose. The underground supplies are them- 

 selves of course regulated by the rainfall which is very variable both 

 in quantity and as to the period in which it occurs. The registry of 

 rainfall at the Nundydroog Mine during the last 4 years is as 



follows :— 



Amount of 

 Year. rainfall 



in inches, 



1896 28-63 



1897 3i"47 



1898 44'oi 



1899 lS'29 



As a rule the wettest months are September and October 

 (October being generally the time of the N. E. Monsoon) ; but 

 April, May and June are also generally wet months (S. W. Monsoon). 

 Practically no rain falls from December to March. 



The water is stored in masonry tanks, the storage capacity of the 

 larger mines being from three to nine million gallons. At the Mysore 

 Mine, the water required for milling purposes is stored in a tank 

 having a capacity of 4! million gallons, and the water from the mill 

 is returned from the slimes catch-pits to this tank. There are two 

 other large storage tanks having a combined capacity of 3! million 

 gallons, and several small condensing tanks at the compressor and 

 mill-houses. These tanks store water from surface drainage, also 

 that pumped from the mines and that pumped from the water-shafts, 

 situated three miles distant from the mine. 



During average years, the supply is quite adequate for the re- 

 quirements of the mines, but to cope with the short-fall occasioned 

 by years of drought, the construction of a large dam in the neighbour- 

 hood of the mines to catch and conserve the surplus surface drainage 



