82 TIN MINING IN PERAK. 



they come into contact with the mercury and remain until the 

 time comes to clean up the sluice. It is evident that the amount 

 of water, and the size and grade of the various parts of the 

 apparatus, must be so adjiisted that the sand and gravel in no 

 part of the length of the sluice shall settle down into a compact 

 mass at the bottom of the sluices or between the riffle bars, 

 for wherever packing, as it is called, takes place that portion of 

 the ajiparatus is rendered inoperative. The whole of the 

 material shoidd be in a state of movement, gently, on the tables 

 where the fine gold is to be caught, but still in motion. 



The difference of the conditions between the requirements 

 of a sluice to catch gold and to catch tin are as follows ; the 

 catchment area must be much larger and, as the tin cannot 

 be caught and retained by solution in mercury, the sluice must 

 be cleaned out at moie frequent intervals or the tin will drift 

 down the sluice and pass into the tail-race. The object aimed at 

 is to jjroduce on the tallies and between the riffle bars a rich 

 concentrate, which can be periodically removed from the sluice 

 and washed in an ordinary washing box until it becomes suffi- 

 ciently pure to be sent to market. 



In the year 1892 the first attempt was made in Perak 

 to work tin land by hydraulic sluicing, at Teluk Bharu, about 

 two miles from the town of Ipoh, in Kinta, by the Leh Chin 

 Mining Company, under the management of Mr. F. D. Osborne. 

 Eight -inch pipes were laid down from the intake at the foot of 

 the Kledang hills to bring the water down to the mine. They 

 were about two miles long, and there was a fall of some two 

 hundred feet, the monitor being used with a two -inch nozzle. 



The land, however, proved to be unsuited to this method of 

 working, as it was too flat and there was insufficient fall to 

 allow the tailings to discharge into the Pari river. The result 

 was the tailings rapidly banked up, filled the sluice boxes 

 and stopped all further work until they could be dug out 

 and the channel cleared again. The Grovernment also objected 

 to the tailings being discharged into the Pari river, as they 

 would be likely to silt up the Kinta river, which was then, 

 and until the railway was opened, in 1895, the highway on 

 which all the traffic with the port of Teluk Anson was borne. 



The pipes and monitor were therefore taken up and moved 

 to Gopeng, where they are employed to bring water from the 

 hills to near the town of Gopeng, to work the land belonging 

 to the Gopeng Tin Mining Company, Limited. The erection 

 was begun in August of 1892, and was carried on under the 

 direction of Mr. E. E. Pike, who resigned his appointment 



