320 BROWN & HERON: GEOLOGY AND ORE DEPOSITS OF TAVOY. 



parties of coolies used the water and have won as much as two tons 

 of concentrates in a month. The cost of running the pump was 

 Rs. 600 per month. The water is collected in miniature dams 

 which when full are suddenly emptied and the water allowed to rush 

 down the hillside through the sluice. 1 



At Wagon South a steam pumping plant was erected to deliver 

 2,000 gallons per hour against a head of over 700 feet, to treat 

 ground proved by pitting to contain approximately 2 lbs. of concen- 

 trate per cubic yard. 



Concentrating Pans. 



As for treating rich residual deposits when it is not possible nor 

 expedient to break them down by pressure water, they may be ex- 

 cavated by hand and the concentrates recovered in a pan similar 

 to those used in washing gem gravels in the lluby Mines in Burma 

 and the diamond fields of South Africa. This method has been 

 adopted with some success by Mr. A. H. Morgan in the case of the 

 softer deposits on the southern extension of the stockwork at Pagaye. 

 The pan is 10 feet in diameter and has the usual accessories of grizzly, 

 rotary screen and picking tables. It is driven by a 20 H. P. 

 Hornsby-Akroyd oil engine that also drives a 3 inch centrifugal 

 pump which delivers 150 to 200 gallons of water at a height of 65 feet, 

 sufficient for the whole outfit. The pan saves a larger proportion of 

 fines and does the work with about a third part of the water required 

 in hand working by native sluicing methods. The costs are high 

 but on ground which carries good values the work is profitable. 



High Pressure Hydraulic Plants. 



Once it is decided to bring in water to any deposit, especially 

 if the ground to be treated is situated at the foot of the hills and is 

 buried under poor or barren overburden, as is so often the case, 

 the question has to be settled as to whether it is not better to break 

 it down and wash it in one operation. The late Mr. C. M. Lyons. 

 O. B. E., who spent over six years in Tavoy and possessed unequalled 

 knowledge and experience of hydraulic machinery under local con- 

 ditions, was induced to publish his matured views for the benefit 

 of others engaged in the industry. The following notes are taken 



>G. N. Marks. (18), p. 27. 



