A NEW DESCRIPTION OF BLASTING POWDER.

Tuapeka Times, Volume III, Issue 159, 23 February 1871, Page 7

A NEW DESCRIPTION OF BLASTING P OWDER.

A number of interesting experiments wereraade on Tuesday atLeake's quarry, Footscray, (says the Melbourne :t Age"), with a new compound called Longbottom's safety blasting powder, in the presence of several gentlemen, connected with mining operations. The inventor claims for the compound certain advantages over the ordinary blasting powder, namely, that it can be subjected to any amount of friction, and is perfectly safe in transit or use. It will not explode by pressure, or by contact with fire, unless confined as in blasting. Its force is estimated at from 25 to 30 per cent, stronger than blasting podwer, and it throws off comparatively little smoke, and this lighter than smoke from common powder. The cost of material and manufacture, it is estimated will not exceed 4d. to sd. per lb., and it may be sold at Bd. per lb., retail, this being considerably less than the cost of blasting powder now in use. A number of holes were drilled ready for the experiment, with one exception, perpendicularly into the rock. The first of these., which was 3 feet 4 inches in depth, was charged with 20 inches of of, this powder, and fired off. The stone was split down seven feet, but not dislodged, being jammed in by the rock on either side. No. 2 was driven into the face of the rock about 13 inches, and charged with 4 inches of powder, the result being that the stone was split in all directions. No. 3 was a hole with a depth of 1 foot 7 inches, charged with 6 inches of powder, and a quantity of stone was displaced. No. •i had a depth of 3 foot, with 18 inches of powdei 1 , and the force of this charge split the rook dawn 8 or 9 feet. No. 5 with a depth of 2 feet 10 inches, had 20 inches of powder, the hole bein.j driven 3 feet from the side of the rock. A large mass of stone, weighing about 3 tons, was displaced, and thrown a distance of 3 or 4 yards. No. 6 was driven a depth of 17 inches, and charged with G inches of powder, and another largo peice ab>ut the same sizo was dislodged. No. 7 was 8 inches deep, with 4<\ inches of powder, and the rock was split in various directions and a quantity thrown down. No. 8 was a depth of 2 feet 1 inch, with 7 inches of powder. In this trial the hole was made in a more favourable position for the charge to take effect on the rock, the result being that the stone was was split to a considerable depth, and a large quantity dislodged. In all these cases the chirges of ordinary blasting powder would have been much larger to effect the same results. For example, in the third trial the charge would have been 9 inches, in the fourth 24 inches, in the fifth 30 inches, iv the sixth 9 inches, and iv the eighth 12 inches. Some experiments were also made to try whether the powder would ignite by friction, and it was found that it would not. It was also stated that in cases of charges missing fire, the tamping might be withdrawn without danger of explosion, and if afterwards a spark fell on the powder it would not explode, but merely burn awa\ r . The gentlemen present expressed themselves satisfied with the results of the experiments, and spoko in high terras of the value of the invention. The proprietor of the quarry is so convinced of its value that he use> it constantly in preference to any other kind of powder. As at present there are over 700 tons of blasting powder imported annually into Victoria alone, it will be an advantage to the colony if the colonial-made material can supplant the English article.