MINING METHODS. 325 



wood dam behind the barge, the solids settle down and the water 

 returns to the nozzle pump. 



Examples of high pressure hydraulic installations in Tavoy. 

 Wagon.— At the Wagon mine of the Wagon-Pachaung Wolfram 

 Mines, Ltd., detrital ground is successfully treated by monitors 

 with 1 inch to 1£ inch nozzles, working under a head of 230 feet. 

 The length of piping used from the intake on the Pya chaung is 

 about a mile. The intake is set in a small diversion dam of ferro- 

 concrete and the appliances were designed and erected by Mr. H. G. 

 Mathews. The ground is thin and overlies decomposed granite. 

 Owing to the absence of large quantities of stones the tailings 

 are soft, and as the mine lies at some distance above the elevation 

 of the ' main drainage channel of the neighbourhood, their dis- 

 posal presents no great difficulty. Woik can only be carried on 

 during the monsoon. 



Hermyingyi.—At the Hermyingyi mine an old terrace deposit 

 at the head of the Maungmeshaung valley is treated by monitors 

 with nozzles of \\ to 2£ inches, working under a head of 220 feet. 

 Water is available only during the rains, and is taken from one of the 

 flumes which also supply the ground-sluicing requirements of 

 the mine. The ground is exceedingly heavy and over 80 per cent, 

 consists of large boulders and stones, some of which have to be blasted 

 and removed by hand. Yet the total cost of the wolfram and cas- 

 siterite concentrates produced is only Re. 1 per viss (i.e., per 3-60 lb.) 

 and in lighter ground with better facilities, where a larger quantity could 

 be cut per month, the concentrate ought to be produced at a 

 quarter this cost and consequently much poorer ground could be 

 made to pay well. 



Dredging. 

 Dredging operations proper, for tin ore, are only carried on in 

 one locality in Tavoy at present. This is near Taungthonlon in the 

 valley of the Hindu chaung, about 30 miles from Tavoy town on 

 the Siam road. The area was originally held under a "native 

 methods" lease by one Lubhai Sahib, who carried on small scale 

 sluicing operations, smelted the cassiterite in Tavoy and sold the 



metal locally. 



At a later date the area was sold to a Melbourne company 

 known as the " Hindu Chaung Tin Dredging and Mining Company." 



