A FEW REMARKS ON THE SAVING OF FINE GOLD. TO THE EDITOR.

Otago Witness, Issue 2082, 18 January 1894, Page 13

A FEW REMARKS ON THE SAVING OF FINE GOLD. TO THE EDITOR.

Sib, — Among the many appliances used in the saving of fine gold, cocoanut matting is now generally adopted for covering the bottom of sluice boxes, but this will cot remain long in an effective condition, as it becomes silted up smooth and firm like a board, and it is therefore not all that could be desired as a gold catcher. Again, very fine gold, known as * 'colours," when clean and dry, if placed carefully in small quantities on the surface of still water, will float about for a time like so much sawdust. This is well_ known to anyone having experience in gold-mining, and such being the case I do not think it unreasonable to suppose that this class of gold when intermixed with the heavy sludge from a sluicing claim or dredge would travel for miles without coming into contact with the bottom of a sluiccbox matting or anything else, and yet the very finest of gold may be separated from almost any kind of washdirt in a gold-dish — that is to say, on >ts being washed it will collect together and lodge on the bottom of the pan, although it cannot be panned off like coarser gold, and this may be accounted for by the simple fact that particles of gold, however floe, will sink down through water at a higher rate of speed than particles of any lighter material, irrespective of their size. Taking this as a starting point, I have planned a kind of separating sluice box which, as I am not now located in a mining district, I have not had the opportunity of putting to a practical test, but were it made known through the Witness it would probably be taken up and worked upon by some of our mining friends, who may turn it to good account. My plan 1 will try and explain as follows : —

The sludge or tailings to be treated are discharged from the end of a short box running downhill at an aDgle of about 45deg, and fall on the surface of a body of clean water running in a box directly underneath set at the same grade. The gold it contained, being the first to reach the bottom of this lower box, could, I think, be separated by having a break in the bottom of this box where the gold would touch, the part below this point being raised, leaving a snace for the gold to pass out. The remaining "dirt taking longer to sink would thus fall on the second or lower part, and be carried off as refuse. I will hero give a diagram, which will make it more easily understood :—

I bhould like to hear the opinions of practical men on '.the feasibility of my plan, and have no doubb you will give space for any comments thereon. — lam, &c, John Gedd£s. Winton, January 8.