THE DIAMOND DRILL.

Western Star, Issue 429, 23 March 1881, Page 3

THE DIAMOND DRILL.

The Stawell mining correspondent Of the Melbourne/ 1 Argus” gives, some information With respect to the workiitg of diambnd/drillW in 'connection with.quart 1 ? inining in that district, which maw be of value to New Zealand reefers. Speaking of the halfyearly meeting of the Scotchman, a Company,.he says: r ,-> j “ There was a very long discußsion as tb ;I fihe r best mode of working the mine, or father the most economical way of reaching the.reef bored into by the diamond drill, which would costpdssiblv £2OOO. It was suggested that other/companies bo asked to bear a portion of the expense, the benefit to them being that crosscut drives would be put into their ground and "prospect it as'the'drivo proceeded. As showing the growing feeling here, it may be noticed that all were of opinion that the mining:: companies/ of the ; placo should combine and purchase diamond drills for thexHselves; - that now leased from the Government being wholly insufficient for the local requirements. It is not unlikely that before long a company will be formed for this purpose; Now that the diamond drills have been so thoroughly proved, they will before long quite revolutionise the present system of mining. No more machinery- will be erected on mere speculation as hitherto; and no more drives put in on the chance calculation of mining surveyors; in every case tho diamond drill will be the pioneer to tell companies what awaits them, and where they are to sink and drive. Their use will to. a great extent take away the merely speculative element from mining. During this week the ■ Mitchell’s rockborer has been submitted to some very severe tests, out of which it has come triumphantly. The ‘"country’chosen to operate in was of the very hardest character. So.d'ffer->

ent, indeed, is the nature of the quartz in the St aw el I mines from that met with in Sandhurst that Mr Mitchell, who was present, expressed himself as almost despairing of his drill doing the work. The first hole put in by the borer was 4ft XOin in depth, the utrnost depth to which the drill used would go.. This was bored in 19i minutes, including all stoppages. Some of the other drill holes were not so successful owing to unforseen delays, but that stated may be put down as the average speed, everything wanted being on the spot, and all in proper working order. Finally a depth of 9ft Sin had been accomplished by the borer iri 53 . minutes, including stoppages—a feat which has never before been equalled at Stawell by any other roekborer. Hitherto the National roekborer has held the palm, hut it must now give place to Mitchell’s in Sta Well favor. The stroke is twice as quick and much stronger, so that it accomplishes nearly double the work. It seems so far to excel the National, that it will bore in three-quarters of an hour what it would take the latter an hour and a quarter to do, and its work in that time would take five men an entire shift of eight hours to accomplish), . I mriy point out that this is a much superior trial to any kind that could be given at the Exhibition. The drills were in the mines, and at the exact work.for which they-were made, arid that, too', in perhaps the hardest ‘country’ in Victoria. This borer was purchased for the United Scotchman’s mine, to reach the place pierced by the. diamond drill. ’ln this mine the aircompressor .is fixed in its place, and when the connecting pipes from the borer to the compressor are attached active work will begin.’’