"After great effort, numerous trials, many failures and some large losses, this system of gaining gold has been evolved from crude beginnings into a systematic and satisfactory method of mining. Dredging for gold is now attracting attention and bids fair to become an established form of mining for that metal. In New Zealand, where more work of this nature has been done than elsewhere, the evolution of the industry has been the work of years. The rivers upon which dredging operations are carried on are swift-flowing streams, subject to frequent floods, having a considerable depth of gravel, with boulders and runs of pay dirt interstratified. The conditions are, therefore, not the best for economical and successful work, and it is not surprising that many failures have occurred. The runs of gold are, however, often extensive and rich, and operations carried on upon such reaches have in a number of cases given satisfactory results. "The improved form of dredge is a double pontoon, with ladder and chain-bucket arrangement between. Screens separate the coarse from the fine material. Wide sluicing tables catch the gold, centrifugal pumps supply the water, and waste material is handled by elevators. The power is usually steam, although electricity is used in a few instances, where conditions are favorable. The dredges vary in size and capacity, but are now built of large size and great strength. Twenty thousand dollars is the cost of a large dredge with all the latest contrivances. Under favorable conditions, material has been handled without loss that only yielded a grain of gold to the cubic yard. The real cost in actual continued working is believed to be very much in excess of that figure where average conditions exist. "One dredge on the Clyde side of the Shotover, working to a depth of twenty feet below water level, lifted 40 tons per hour when operating. The profit on eleven dredges for the four weeks ending July 24, 1897, was an average of $2,686 for each dredge. "So far in this country (United States), with a few exceptions, dredging operations for gold have not been financially successful. From crude beginnings, however, the machines have been rapidly improved and perfected, until now, in some localities, dredges believed to be the most complete yet constructed are being put in operation, and results are promised, not yet attained, in the way of economical working and high percentage of saving. During the last few years, a number of dredges have been operated in California, British Columbia, Idaho, Montana and Colorado, but with poor success. Very few prove themselves capable of paying their way. Some of the machines were faulty within themselves, others were entirely unable to cope with the swift currents and large boulders of the streams upon which they were operated. This latter is said to have notably proved the case with the dredges tried upon the Frazer and Ouesenelle rivers.