An Improved Sluice-box.

Cromwell Argus, Volume IV, Issue 187, 10 June 1873, Page 7

An Improved Sluice-box.

Among the novel mechanical contrivances on view at the Intercolonial Exhibition now open in Sydney, is Coate's improved sluicing apparatus, which is thus described by the Sydney Morning Herald: — "It is a long sluice-box, intended to be made into two or three compartments to telescope into each other, though the sluice at present exhibited is all in one piece. It is about 16 feet long and about 12 inches wide in the clear, and is divided into three portions. The upper part in which the washdirt is first fed consists of a stout cast-iron plate, having six flutes, two inches apart, ridged into its upper side, and pierced with a number of three-quarter inch holes, through which the stuff passes as it becomes disintegrated by the water brought on to it and by the action of the fork by which it is worked up in tlve ordinary way by hand. At the end of the plate is a screen set close enough to prevent the passage of large stones, which are there collected and forked out in the usual manner. It is between this screen and the head of the sluice-box that the wasdirt is thoroughly disintegrated bef( ire being brought under the action of the ripples which succeed. These ripples are of the best cast-steel, and are set in a strong wrought-iron frame, six feet long and twelve inches wide, in such a way as that by the action of a screw at either end they may be raised or depressed at pleasure, and set to any angle. In fact, they may be closed down so as to allow of a free passage over them. The blades are set two inches apart in the frame, and are made para-! bolic in shape, the curve being in the direc-1 tion of the flow of water. As the stuff is washed down over these blades or ripples, the specific gravity of gold causes it at once to fall from the edge of the curve into the opening left between that and the rounded curve of the next blade, whilst the lighter stuff is carried off by the force of the stream. Below the blade-ripples are a series of short blanket-tables which may be extended to any length required, divided from each other by an ordinary wooden brake, or ripple. This sluice has been examined by many miners, who have all expressed themselves pleased with the principle on which it is constructed. This apparatus was tried with others yesterday by the judges, and some 5 dwts. of gold having been thrown into about a ton of rubble, the gold was all recovered easily in ten minutes."