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POPULAR SCIENCE MONTHLY 



The other method is in diving to the bottom of rivers and taking 

 out the cascalho from there. This method is confined to a small 

 section of the district where the river runs through a natural canal 



Fig. 4. Method of Mining; removing Subsoil to expose Cascalho. 



cut into the rock. The diving can only be done when the river is 

 low and is chiefly done naked, though there are a few diving suits in 

 use. The naked clivers descend a pole planted in the river and fill a 

 sack with the cascalho, which is taken on shore for washing. The 

 ability of some of these men to go to great depths and stay under for 

 long intervals is extraordinary. In some places attempt is made to 

 work the old river bed, but this is done with great difficulty, as water 

 will seep in almost as fast it can be bailed out, leaving little time 

 for the collection of cascalho. 



Whatever the method of taking the cascalho out, the great de- 

 sideratum is an abundant supply of water for washing. Where it is 

 possible water from mountain streams is conducted down by ditches 

 and flumes, and into these the cascalho is thrown. It is worked with 

 a hoe. by which method the lighter particles are washed away, thus 

 leaving a greater concentration which includes the diamonds and 

 carbons. The concentration is taken out of the ditches and accumu- 

 lated until the week's end, when it is laboriously further concentrated 

 in bateias. 



This final concentration and wash-up requires considerable dex- 

 terity as well as strength. It consists in revolving and shaking the 

 bowl that the portions of heavier specific gravity accumulate in the 



