Some dredges have a capacity under favourable conditions of over 2000 cub.
In working auriferous river-beds, dredges have been used with considerable success in certain parts of New Zealand and on the Pacific slope in America.
The dredges used in California are almost exclusively of the endless-chain bucket or steam-shovel pattern.
The water necessary to the process is pumped from the river; as much as 2000 gallons per minute is used on the larger dredges.
In South Island the river-beds of Otago province have been successfully worked by means of dredges, and good returns secured.
