THE DIAMOND DRILL.

Otago Witness, Issue 1419, 1 February 1879, Page 20

THE DIAMOND DRILL.

After many delays and disappointments, the Government diamond drill on the Great Southern Compan v 's lease at Bendigo has been started. A good number of miners, mining managers, and others interested in the machine put in an appearance on the first day. Prominent amongst those present were Mr S. G. Cole and the directors of the Great Southern Company. Contrary to expectations the ariangements were not fully completed by the expected time (three o'clock), and it was nearly live o'clock before everything was in readiness. The start when it was made, was most interesting to all present. The hydraulic apparatus was first put in play, when it was found that several joints and couplings required securing up, and this work took a little time. This trial showod the working of the hydraulic feed to perfection, the machinery which forces the drill downward being raised and lowered several times to see that everything was right. Then the steam power was applied, showing the circular movement of the drilling apparatus, and the working of the oscillating cylinders; a triumph of mechanical invention in themselves. When everthing was ready, the first length or tube, with the diamond bic screwed on, was inserted in the tube of the boring machinery, and lowered to the bottom of the fixed iron piping, which is sunk to a depth of 9ft below the level of the surface. This first tube is 12ft in length, with the diamond bit at one end, and a setting of diamonds at the other, to ensure ita passage freely into the ground. The tube has spiral grooves running up the outside of it, up which the water and defo'is como as the boring is proceeded with. Into the end of this tube was screwed one of the ordinary boring-rods, which are smaller in size and without the spiral grooves on the outside, but are bored for the free admission of the water. At the top of this rod, a swivel-joint, fitted to a length of hose was attached, which allowed of the water being foiced through it, and the rod itself revolving without hindrance. The first length, with the diamond-bit, having been lowered to the rock, the screws at the end of the boring apparatus were fixed, and the steam being applied the bore began to revolve. Mr Griscom managed tbe first few feet himself, -as the opening of the bore hole is a delicate operation requiring great care, as the success of future operations depends greatly on the bore being commenced properly. When a few inches had been bored the drill was started in real earnest, and about 6ft drilled in an incredibly short space of time ; the machinery acting very well. After this one of the hydraulic couplings gave way in the india-rubber tubing, but this was quickly repaired and about Bft in all bored. Tbe boriDg rod and bit is 2^in in diameter, and takes out a core lfin in diameter. Everything about the machine seems in first-rate order, and there should be no delay now in the operations. — Bendigo Advertiser.