MACHINE TUNNELING- IN CLEVELAND.

Tuapeka Times, Volume VI, Issue 275, 8 May 1873, Page 7

MACHINE TUNNELING- IN CLEVELAND.

The Machine Tunneling Company, of London, a joint-stock undertaking which has been specially organised with the object of working the ingenious patented invention of Capt. Beaumont, E. 8., M.P. for South Durham, have now got fairly to work ; and the work they are doing fully realises the most sanguine expectation. Several sets of prospecting machinery are already in operation. In Wales, and in the Furness district, the operations have lesn witnessed by practical men with wonder and delight; and now in Cleveland, as mentioned in the " Times " of the other day, a perpendicular bore-hole has been driven through one of the new iron royalties, with results not only gratifying, and likely to be commercially profitable but also instructive. The Machine Tunneling Company have just completed a top bore-hole of 689 feet, 4 inches, on the estate, and undertaken at the instance of the Staughow Ironworks Company. This work was begun on the 7th of October last, and continued during the short days np to the 14th of December, when the bore-bole was complete. In the first fifteen working days a depth of 107 feet was reached, 86 of which was driven through hard sandstone, and another hard rock thick studded with crystals of quartz. Another twelve working days brought the borehole down to the well-known shale overlying the ironstone which was the object of search. During those twelve working days, the bore-hole had been sunk 220 feet, and the shale was reached at a distance of 368 feet from the surface. Unfortunately, at this period, the weather became uncertain — we should, perhaps, rather say became decidedly un propitious — the pumps were frozen, and considerable delay consequently ensued. On operations being resumed, however, the remaining depth of about 300 feet was satisfactorily completed on the 16th of the following month. An excellent sample of valuable ironstone ends the nearly seven hundred feet core withdrawn from its beautiful penetration through the stratification of Cleveland. Thus, in sixty short days, including all stoppages and the delay from frost, the Stanghow ironstone has been found ; and a good core, showing a complete section of the underlying strata, obtained. Specimens of this core geologists and mining engineers may inspect at the office of the "Northern Echo." Those who have no opportunity of doing so will understand our description thereof, when we say that the Machine Tunneling Company's apparatus withdraws from the line of their bore-hole, instead of the pounded sludge and debris which results from the oldfashioned, tedious, and laborious system of boring, a perfect specimen of the rocks it passes through, of about the thickness of an ordinary office ruler. A ' piece of the shale, found 623, and of the ironstone found ut 689 feet depth, in the Stanghow royalty, now lies before us : as perfect specimens as could have been obtained had the shaft been sunk to those depths and now at work. The instrument by means of which the boring was eff< cfced appears to be not only a wonde.rful economiser of time, but, for all practical purposes, an irresistible application of dexterous mechanical force. The hardest grit and flint

stones are cut as clean as the softest shale. No doubt the machinery employed is of a costly character, but it appears to stand its work well. More than that — if anything is to be credited to it for saving of time — an element which in these days is not likely to be lightly valued — the cost of boring by machinery will virtually be less than that by the old processes. The actual cost of the machine boring is only a small fraction more than that | of boring by hand. Two years at least would have been required to go through the stratification which has been so satisfactorily pierced for the Stanghow Ironworks Company in less than two months." Messrs Brogden and Sons have the right to use the patents in New Zealand ; a specimen of the core, cut out of sandstone, has been placed in he Napier Athenjeum.