MACHINE TUNNELING IN CLEVELAND.

Westport Times, Volume VII, Issue 1064, 18 April 1873, Page 4

MACHINE TUNNELING IN CLEVELAND.

The Machine Tunnelling Company, of London, a joint-stock undertaking which ha 9 been specially organised with Ibe object of working the ingenious patented invention of Capt. Beaumont, RE, MP, 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 been 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 oniy gratifying, and likely to be commercially profitable but also instructive.

The Machine Tunnelling Company have just completed a top bore-hole of 689 feet, 4 inches, oa the estate, and undertaken at the instance of the Stanghow Ironworks Company. This work was begun on the 7th of October last, and conliuued during the short days up to the 14th of December, when the bore-hole 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 quarts. Another twelve working days brought the borehole down to the well-known shale overlying the iroustone 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 become decidedly unpropitious—the pumps were frozen, and considerable delay consequently ensued. On operalions being resumed, however, the remaiuing depth of about 300 feet was satisfactorily completed on the 16th of the following month. An excellent sample of valuable ironstone ends the the nearly seven hundred feet core withdrawn irom this beautiful penetration through the stratification of Cleveland.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 j and a good core, Bhowing 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 Tunnelling Company's apparatus withdraws from the line of their bore-hole, instead of the pounded sludge and debris which results from tho oldfashioned, tedious, and laborious system of boring, a perfect specimen of the rocks it passes through, of about, the thickness of an ordinary offiVe ruler. A piece of the shale, found 623, and of the ironstone found, at 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 tho boring was affected appears to be not only a wonderful 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 deubt the machinery employed is of« 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 boriny by hand. Two years at least would have been required to go through the stratification which has been "so satisfactorily pierced for the Stangbow 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 the Napier Athenasum.