Thames Jesting Plant.

Auckland Star, Volume XVIII, Issue 180, 3 August 1887, Page 8

Thames Jesting Plant.

(To the Editor.)

-l ß> _Your able leading article on the boye subject is liable—unintentionally, no oubt,—to create a false impression as to ho value of the gold and silver ores of the loromandel, Thames, Ohinemuri, and *c Aroha districts, in that the assays üblished imply, although they do not iy so, that the samples assayed and the sturna given are a fair average of the oetaliferous lodes mentioned. Whereas, n truth, the real average is only about onewentieth of that published. There is now n evident desire on the part of many •wners of mines, some of them partially vorked out (without further prospecting vh.ich.may or mny not lead to the discovery >f payable ore), to induce Home capitalists so invest in our mines on the basis of our If these attempts are successful, no doubt i little English capital will be spent here, but as the subscribers will inevitably lose their money, it will ultimately do not only the mmmg ■districts, but Auckland and the whole colony harm. With reference to the proposed testing plant; .I think it is a step in the right direction and have subscribed towards the cost, bub that it will result in the discovery, for the public benefit; of a new payable process, I very much doubt. As if any such discovery were made, although it was by means of public money we sKoufdfTnd'if patented for the private benefit of the discoverer, . . , The possibilities in this way are rather limited, as was very truly explained by Professor Brown during his lecture at the School of Mines, and may briefly be described as—o) Hand-picking the ore, rejecting the worthless portions, which I^1 'at ! present impracticable from the want of. skilled cheap labour, and \i) crushing the ore as delivered trom the aiines and saving the free "gold on amalgamated plates, this is the usual process and because of the abundance of water power, Much che cheapest method. The difficulties commence when, we try to recover the gold and silver remaining in the tailings, and I may here remark that the proportion lost that way is very generally over estimated. I therefore propose showing how even that may be prevented whenever»the value of the bulk is sufficient to pay cost of treatment, andit is here that the proposed experimental plant will be valuable. The tailing pits at present attached to crushing mills are far too small, they should be much larger and-shallower, then after crashing in the ordinary way, the tailings could be easily cjeancd out of tho pits, fairly sampled and assayed. Tho gold obtained within the battery and that contained in the tailings •would show the actual value of the ore delivered;. If the. assay showed them to be payable, a portion could bo sent to the experimental plant of the School of Mines, when for a moderate fee the owner could be advised as to the best method of obtaining the valuable contents as the result of actual working experiment. —I am. etc., George Denbv:. Thames, 27th July, 1887.