DIVING FOR GOLD

Daily Telegraph (Napier), Volume 58, Issue 164, 13 August 1929, Page 9

DIVING FOR GOLD

NEW DREDGING DEVICE.SUCKS PRECIOUS METAL FROM RIVER BEDS. PIONEER'S vSUCCESSFUL AT- . TEMPT. IIow a diver hi conventional rig, having in liis liand tlie end of a kose attached to a steam pump, manages to suck up gokl from a California streaui already "worked" by early gold seekers as well as tliey could do it by liand, is doscribed b;/ Floyd Blancliard ju Tlie Engineering and Miiiing Journal (New York). The writer asscrts tliat this is tbe first successful attempt to recover gold in this way. The earliest plant constructed was wreckcd by a flood 111 1927, and the prescnt one replaces RSavs Mr Blancliard: "Deposits of plit'er gold in the ehannels of Tuonntain streams, particularly those wliicli carry mucli water all the vcar round, are usutllv =o confin.ed i]i j a dee]i navrow gorge that small possibilitv cxists of diverting tht water into nnotlier cliannel to make possible a elcan-un of the gold. To oyercome these diffieulties a new and interpsting metliod, a eombination of a diver and a ccntrifugal pmnn. has been dpvhecl. and is in successful operation m Cnliffirnin

LARGB QUANTITY OF GOLD. "The dredge is beiug operated in the middlo fork of the Fcatlier River, near Fvanaka kar. This gold-bearing bar has been worked by pioueer miners in tbe early days, and in later years by various prospectovs. The gravel has been worked as far out into the stream as it was possible for men to wade. Below the kar is a large basin, about 1000 feet in lengtli and varying from 100 to 300 feet in widtli, which has served to catch a large quantity of gold-bearing gravel and sand. "Mac-hinery necessary for the dredging operation is mounted on a wooden tnill. A six-incli gravel pump is driven bv a four-cylinder gas engine. Attached to the suction of the pump is a flexible rubber hose, hung from a short swinging stiff leg denrick on the bow of the hui). To operate tlie suction hose a diver using a complete divmg apparatus is required. He is ahie to work at any point from near tlie surface to a deptli of 30 or 40 feet. T-no iee cold water necessitates the use ot diver' s mittens, but otlierwiss no special cquipment is necessary. IN THE CREVICES.

"The diver, after heing drcssed in his hcavy rubber suit, steel lielmet, lead belt, steel-sliod shoes and watertiglit lhittens, climbs dowu a ladder on the bow of tho hull and, grasping the end of tlio rubber suction lioSe, moves it about in the erevices of tlie bedroek ► and between tlie loose rocks distributed over the hottoni of the river bed. In places wliere the gravel is covcred witli stone s it has heen found advantageous to first clear out a part of the larger rocks, "Tiiis is done hy means of a steel .wire. The drivcr attaches tlie wiro to a large rock, signals the engineer to pull awav, and the rock is dragged out } of the way. When a great many rocks are eiicountcrcd that are just .oversize for the pump, a net is used. The nefc is dragged into position near the spot which tho diver desires to clean out, and, when filled by the diver, it is dragged back out of tlie way and dumned. "The gravel pump discharges into a long sluiee box nvovided with steel shod wooclen trap riffles, between the bars, en which quicksilver is placed to amalgamate the gokl.

PRACTICALLY CONTINUOUS. ."Operation of tlie dredge is practicaliy continuous during daytime. The diver stays down about "two hours at a time, and tlien comes up for a short rest. Three men are needed to operate the dredge — the diver. his assistant, who tends the sigual line and air eonipress6r, and an engineer to -wgtcli the pump and engine'.- While tlie dredge is working it is kept pointed up stream by means of raooring lines, so tha't the discharge from tlie gold-'; saving sluice is down stream back of the diver. therebv permitting him to work always in clear water and to be ahle to see what he has to do. Owing to the shallow deptli at which he ordinarily works no serious after effects are experienced. The eold water causes the greatest ineonvenience, but tliis is overcome hv the continuous activjtv necessitated in moving tho suction hose. "Varinus attempts to recover placer gold and tin with a centrifugal gravel pump have heen made, but none had nroved successful tintil the abovedescribcd dredge was huilt."