ROCK RENDER.

Thames Guardian and Mining Record, Volume I, Issue 274, 24 August 1872, Page 3

ROCK RENDER.

The annoucement of a public trial of the Rock Render in Coombe’s claim, Glenmore Otago, gathered together there on Friday last a considerable number of miners and others interested in the experiment. We learn from the Otago Daily Times that the drive prepared for the shot was 3ft by 2ft, running 117 ft into the hill, with a 7ft Tat the end. In nine minutes after tho fuse was lighted, the charge exploded, and twenty or thirty yards of the ground’s surface was seen to be heaved up about a foot, and smoke to issue from cracks in the hill over the back of the drive. To judge from appearances the quantity of cement and stuff displaced will probably prove something like 5,000 tons. Altogether the test was a very severe one, as will be seen from tho figures given, and although the proprietors of the invention have determined, before laying claim to absolute success, to wait ten days, until the water lias been laid on and has found its way into the fissures of the blast, and so tested its result in the most thorough manner, the miners who had charge of the shot seemed to have no hesitation in at once pronouncing a favourable opinion. While the large blast was being tamped, an experiment on a smaller scale was tried with a two-ton boulder in the centre of the claim. In this stone a small drill was made, and a charge of l£in. placed. Although the quantity of the compound used could not have greatly, exceeded an ounce, the result of this test proved that the title was at least no misnomer. The lioek Render behaved like a giant, calm in the consciousness of his strength. There was no loud report, and no hurling exciting fragments high in air. With a dull thud, like a sigh of resignation to its fate, the stone opened up in many pieces, each of which quietly rolled a few feet from the centre ; and although the shot was most satisfactory in its results, anyone might have remained within a few yards of the explosion without real danger.