(I—3.

tub is run to the amalgamator-house. Amalgamation is effected in revolving barrels actuated by a ulnri r " Plusiaes should be washed every eight to twelve hours, and blankets more fre- • "In the treatment of wash containing gold it should be possible to easilvand at any time alter and adjust the proportions of stuff and water dealt with, also to adjust the hoppers and the fall on the tables, especially when variations in the nature of the ground or in the available water have to be considered. "Experience has proved the value of the sand-box, of separate and direct ducts from the sand-box to each table, of the trough-ripples, and of adjustable parts, but the dimensions and general arrangement of any plant must be made to suit the conditions of the case. In determining the size required the amount of water available is generally the ruling element. From and the experience of those working with tables there should not be less than 10 ft. width of table per sluice-head of water, or 60 cubic feet per minute, and 12 ft. of table or more per head is better In sluicing it requires special experience to keep the stuff moving regularly down the tail-race or the tables may be alternately under- and over-fed. In dredging, the delivery of dirt should be more regular, and therefore require the minimum proportion of water. ■IJ'J 6 end , eavoured t0 ascertain the quantity of wash per sluice-head which can be dealt with by table-washing on a large scale. From measurements and estimates of the ground worked and with carefully kept records of the hour-heads expended in working it, I conclude that the average quantity of ground per hour which one sluice-head can deal with is about 5 cubic yards Ihis result must differ in various cases, because the fall and capacity of the tail-race, the proportions of material which go respectvely over the stone-shoot and tables, and other elements have to be considered In the two cases from which my estimates were made, one fall was of very sandy beach-gravel with a considerable overburden of coarse shingle, while the other had very sandy washdirt with an overburden of blue-reef pug." 0 f^T^w^ B ',- hoN and 3^ h ° W the general arran gements in plan and section of a plant erected at the Waiwhero Sluicing Claim, near Barrytown. It has been found in some instances that the very strong winds have a tendency to lift the adjustable tables at their upper end when fitted with the rockmg-jomt shown. To meet this an improved joint has been designed, which is strong easily faxed, and inexpensive. The table-joist end runs between two studs—say 4inby 2 in— th d Zl tB rh n % T™? °} 2i ?' > } in - ir ? n ' With P erfora ted side. A pin of | in. round iron passes through the studs, joists, and stirrup, making a very secure hinge-joint. The drawing No 4 gives a good example of a small cheap plant if modified in construction so as to have the improved table-joint, separate distributing-ducts, and tables having three strakes of 2 ft. length with a fourth and lowest strake, say, 3 ft. long, and with extra fall of about Hin. per foot

DBEDGE-MINING. As was to be expected as the result of the recent "boom" in both the West Coast 9n( l southern goldnelds, a large number of investors have gained an experiencem wWch disappoLt merit is the leading feature. Numerous dredges have been built and put to work- in some she rs:r4:fno s :s,e";:™e k 42 airrf to be L ° ; ta ° ,Js a > ™ M ™ = were not, in many instances, allowed time to properly consider the requirements of claims (manTof which were inadequately tested), and reliable data for their guidance was frequently ™t Sable As regards the second condition many applicants for shares took little or no troubled mquTre into ZlTtft 8 of , the t claim K s °l th ™ suitability for dredging, and thus claims which mighSablv be worked to advantage by hydraulic mining, but not by dredging, were taken up as dredair ,l claims, with results that any independent person with only a slight aUuvialS 8 mining might easily see could only prove financially disastrous auuviai gom The impetus gl yen to dredging by the "boom" has passed, and as actual work proves the value or otherwise of claims, as well as the suitability or unsuitabUity of the dredge* TempCd th is branch of gold-mining is settling down to a steady industry, which will, it is to be reasonably expected, continue for many years to come. There is little doubt that the returns for dre3 Cer rivers ~Tt ? ™% th ° y6ar but for the fact that so ™ «fS| n ™Ja T § r a mUGh l° nger perlod than is usual - consequently those dredges at work in rapid currents and gorges were of necessity stopped for a considerable portion of the! time removal\t tr e nirre a ;Lr"- S ° f dredgeS *°* «^«

those^tht^vious ShOWS " inCreaSe ° f thirt "dredges as compared" with

* Some of the dredges under this heading have been sold for removal.

42

or; :mg. landing.* Building. Under Removal. Total. West Coast district Southern district Totals 36 147 183 8 25 33 29 30 59 19 73 221 19 294