block” as a heavy iron block or anvil provided with In assembling the various plates the horizontal workings and surface features of gold, silver, copper, notches and perforations which may be used by black- planes are coated with a transparent substance ad- iron, or coal mines. smiths in shaping… … After the plates are securely bolted together, the A GLASS MODEL OF A MINE SHOWING UNDERGROUND edges are ground to a uniform plane on a horizontal WORKINGS. AN IMPROVED TYPE OF SWAGE BLOCK. iron disk charged with sand, and are then smoothed and polished. The top plates, intended to represent by…
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