GREAT BLAST AT THE BLUE SPUR.

Otago Witness, Issue 714, 5 August 1865, Page 4

GREAT BLAST AT THE BLUE SPUR.

(Pr m tb." Tuapeka Recorder )

For some considerable time past, this event has been looked forward to with the greatest interest, and as the time fixed ior firing the mine drew near, this interest manifested itself in a feeling of general excitement. Many were the surmises indulged in regarding its probable results. However conflicting, and even wild these surmises may have been at one period, we have much pleasure in announcing that they have now been finally set at rest, and that every feature of the operation has eventuated in a complete success; more so, we may add, than ever its spirited projectors at one time anticipated.

The claim which has thus been operated upon by blasting powder, to an extent hitherto unknown in the history of gold mining speculation, is situated at the top of a blind gully, upon the right-hand side of the Blue Spur. The gully itself, is known by the name of M'Kenzie's Gully, and passes down the front of the range in an easterly direction, facing the track from the gully township, across the range, terminating; in fCaledonian Point, and leading on to Wetherstones. It was fii st wrought by the person whose name it bears, upwards of three years ago. Mr M'Kenzie flubsequently became a partnerof the present claimholders — Messrs Morrison and party — and down to the end of the last twtlve months they were engaged at alluvial work. About that time the cement was opened up, and three acres weis secured under a leasehold application. At a vast amount of trouble and expense, Messrs Morrison and party brought in from a branch of the Waipori river, situated at a distance of thirty miles from their claim, one of the largest water-races in the district; which no doubt accelerated the success that has hitherto attended their labors.

Preparations for the blasting operations in question, were began five or six weeks ago. At that time it was intended to ,xise only one ton of powder, •with the view of detaching somewhere about 10,000 tons ol conglomerate. Acting, however, upon the advice of Mr M'lntosh, a gentleman who was, upon the recommendation of the Provincial Government, engaged to superintend the operation, three tons of powder were used. The whole of this quantity was deposited preparatory to being fired as follows: — A tunnel was cut into the facing, a distance of 100 feet. At the upper end of the mine two cross-drives were cut 10 feet deep, 5 feet high, and 4 feet wide. At a distance of 40 feet from the mouth of the drive, a third chamber of similar dimensions was constructed on the right-hand side. Two wooden cases, 3 feet 6 inches long, 2 feet 6 inches wide, and 3 feet high, were fitted into each of these chambers, and a half ton of powder was deposited in each case. The facing over the mouth of the drive extended to a depth of 100 feet. On the left-hand side, the conglomerate was cut away into an embankment 100 feet long, and on the right-hand side it was cut in front in a similar way, the cutting on this side terminating at the upper cud in the natural channel of the gully. The ground operated upon, formed in this way on three sides a detached block. Between the upper chamber and the outside of the block, on the right-hand side, 70 feet intervened, and between the lower chamber and the outside, on the left hand, upwards of 60 feet. The powder was deposited in the upper chambers on the evening of Thursday. Tamping wa3 afterwards •ommenced. At nine o'clock the following morning, the mine was filled up t o the neck of the outer chamber ; after this chamber had been loaded, the remainder of the tamping was proceeded with, and at nine o'clock the same evening it was filled up to within 10 feet of the mouth of the drive. The tamping operation consisted of stone walls erected 6 feet apart, the intervening space being filled up with clay and conglomerate. The wires connecting the batteries with the chambers, were placed inside a f-inch composition tube, which was hung along the roof of the mine. Galvanic batteries, composed of 50 pairs of plates each, were used .for firing. The priming wires were placed in glass bottles filled with fine powder, and buried one in the centre of each of the charges. The wires leading to the batteries were dipped in cups of quicksilver. Both the positive and negative wires of each battery were fixed to a wooden sledge brake. The batteries themselves were laid about sixty feet distant from the mouth of the drive, towards the right-hand side. A string was led fiom the lever of the brake, to a safe distance from which it was fired. Such is a brief outline of the various arrangement 3 , which were only completed about ten o'clock oa Friday evening. As already stated, the event was looked forward to with a great deal of interest ; arid on Friday .afternoon and evening, a vast number of people from the surrounding districts congregated at the head of the gully to witness the feat. In accordance

with a preconcerted arrangement, three beacon fires were lighted along the face of the spur, as a. signal that preparations for firing the charges had been completed These fires were lit a few minutes before ten o'clock ; and, as if by magic, the whole extent of the gully seemed to be alive with lighted lanterns, which were to be seen making towards the various ridgea from whence a good view of the ground to be blasted could be obtained. At about twenty minutes to eleven, M'lntosh, in company with the shareholders, retired to the end of the galvanic circuit, and the instant the string was slacked and the brakes lowered into the quicksilver, the explosion took place, which was accompanied by a dull heavy sound. The front block appeared to rise in a solid heap and topple over, crumbling into a pounded mass. The upper block then fell right over the front, and so soon as the sparks and smoke had cleared away, the whole mass was found to have been laid just as neat as if it had been a heap of gravel discharged from a monster truck. So very trifling was the report caused by the explosion, that on-lookers from a distance felt some difficulty in reconciling themselves to the belief that it had actually taken place. All doubt, however, was soon put an end to by the sound of a loud cheer from the top of the Spur, which was heartily taken np by those in the Gully, and carried along from spur to spur until it died away in the distance. Viewed from Caledonian Point, opposite the foot of ftt'Kenzie's Gully, the scene was one not readily to be forgotten. From the time the beacon fires were lit until the charge was fired, three-quarters of an hour elapsed. The night being dark, with sudden gusts of wind, caused the light from the fires to flare against the facing to be blown up, in such a manner as occa c ionally to deceive spectators into the belief that the whole of the doomed block was about to take flight in a direction that would place their personal safety in eminent jeopardy. When the explosion did at length take place, the whole mnss seemed to give a sudden up-heave, and before its full effect could be realised, a perfect cloud of sparks and smoke rose up in every direction, as if a fiery eruption had suddenly burst forth from the bowels of the earth.