GOLD DREDGING APPLIANCES. Miners have now a multiplicity of machines

Otago Witness, Issue 1933, 7 December 1888, Page 6 (Supplement)

GOLD DREDGING APPLIANCES. Miners have now a multiplicity of machines

from which to make a selection. By the last English mail particulars have been received of yet another dredge doing successful work in France, at Lyons and Havre. This dredge is, however, only a fac-simile of Robertson's dredge, recently introduced iuto New South Wales. A description of this dredge, a working model of which was lately exhibited at A. and T. Burts', was given in the Times of 27th October last. Ifc is, after all, the common hydraulic elevator, with the addition of an annular air chamber giving increased force and power to the jet of w&ier. The hdyraulic elevator or ejector is one of the oldest forms of dredging known, and was aotually used by the Carthaginians 3000 years ftgo. Mr Ekberg, an engineer on the West Coast, was, however, the first in New Zealand to demonstrate the working of the hydraulic ejector by means of steam power. There is no reason why steam power bhould not be used, and bo as good and cheap a motive power in many districts and under certain circumstances as water power. Mr Ekberg lately drew attention to and illustrated the complete feasibility of working all alluvial deposits, except in the actual bed of large rivers, by thehydraulie elevator. Working on a dry bottom has an immense advantage over all dredging under water, as no gold can possibly be lost. It appears to have been taken for granted that beach claims and inland flats eteeped in water, such as the Duustan and Waipori flats, can only be wrought by expensive dredging 7 'plant erercted on a pontoon. Never was there a greater mistake. Professor Ulrich could tell the miners of Otago that ground rauch deeper and with a much greater flow of water than any ground here has been successfully wrought in Victoria. Even at Waikaia the other day a flat which has always been believed to be unworkable for water has been successfully tackled. The depth to the washdirt is 23ft, the flow of water 6000 gal per hour, and tho pump, which is but a small one, can lift 23,000 gal her hour. It seems quite clear from this that the sea beaches and wafeer-logged flats of Otago can be wrought much more easily and satisfactorily than has been hitherto thought possible, and without the long delay and heavy expenditure j necessary for working the bed o£ the Molyneux : and other large rivers.