A supplement to Ures Dictionary of Arts, Manufactures, and Mines, : containing a clear exposition of their principles and practice. . madeby Mr. Jones in the Mint, under Mr. Pilchers directions. Fig. 459 shows this is a hopper made of brass, and indicated by the dotted lines; it serves to prevent thescattering of the gold dust by the rapid motion of the file, b is a tube with a slit cut in itsupper and in its lower half; a is a circular file which is made to revolve very rapidly; c isa knife-edge which offers resistance to the circulating blanks when in motion ; d is a glassdish into
A supplement to Ures Dictionary of Arts, Manufactures, and Mines, : containing a clear exposition of their principles and practice. . madeby Mr. Jones in the Mint, under Mr. Pilchers directions. Fig. 459 shows this is a hopper made of brass, and indicated by the dotted lines; it serves to prevent thescattering of the gold dust by the rapid motion of the file, b is a tube with a slit cut in itsupper and in its lower half; a is a circular file which is made to revolve very rapidly; c isa knife-edge which offers resistance to the circulating blanks when in motion ; d is a glassdish into which the gold dust as it is filed from the blanks falls. The blanks are arrangeden rouleaux in a long scoop, by which they are placed in the tube b. The screws g arethen depressed upon pieces of ebony, previously passed into b, until they just touch the MINT. r69 blanks (as shown by the dotted lines in b.) The knife-edge c, whose weight has been pre-viously adjusted by the weight f, is now allowed to descend on to the blanks and carry themdown partly through the tube on to the file. When the file is set in motion the friction. r ii^ ^ 460 gives to the blanks a revolving motion, which is greatly restrained by the weighted knife-edge resting on the top of the blanks, and the resistance offered causes the file to cut thegold away, while the motion of the blanks insures the non-interference with their alreadyperfectly circular form, and the perfect separation of the dust from the blanks. 1,400blanks are reduced in one minute; and as the dust is carefully collected, loss is unknown. The medium are carefully rung by being thrown one by one with some force upona block of iron, and those which do not yield a musical sound are called dumb, and are re-turned with the light rejected and dust to the melting house. About 2 per cent, is the aver-age yield from all causes, therefore 98 out of every lt)0 blank struck out in the cuttingroom ultimately become coined money. The medium
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Keywords: ., bookcentury1800, bookdecade1860, bookpublishernewyo, bookyear1864
