Die Engraving, Sinking, And Multiplying. By Mr. J. Newton, Royal Mint.

covering them with animal charcoal and depositing the whole for twenty-four hours in an oven heated by coke ; they are afterwards withdrawn , removed from the pot , ancl allowed to cool gradually . Next they are taken to the lathe and one end of each is turned . That which is intended to become the " matrix" die ( of which more anon ) is made perfectly flat and smooth , and it is upon this prepared surface that the artists' talent will have to be first expended . The second block , turned

slightly conical , and which is destined to become the " puncheon " may be put out of view pro tern . The engraver addresses himself to . the work of etching in upon the matrix block his approved design , say of the obverse for tbe florin . Assured of having put in his outlines correctly , the work of engraving fairly commences , and only those who have witnessed the operation of die cutting can realise the amount of patience and skill necessary for its successful completion . After many weeks of close and constant

application the design in intaglio will probably be finished , repeated impressions in clay and soft metal being taken adinterim by the artist as tests of the accuracy of his work . Innumerable touchings ancl re-touchings , with the graver , are indispensable to the minute realisation of the design , bufc it at last satisfactorily appears on tbe surface of the softened steel . The letters to form tbe legend and the date are stamped in by aid of punchesancl the matrixor first dieis engraven . A

, , , very important , ancl to the engraver , an anxious operation follows . It is thafc of hardening the matrix . In its present annealed condition it is practically useless , and , therefore , the risk must be run of exposing a very beautiful work of arfc in quick succession to the tender mercies of tlie antagonistic elements fire and water . There is no escaping this , however ; and the artist , if a nervous man , may tremble for the result . His only hope lies

in the excessive care with which the work is clone , ancl the excellence of tlie cast steel of which the die is composed . The preservation unmarreel of the delicate lines ancl tracery which have cost him so many hours and so much exertion is naturally a great consideration . To ensure this , as far as possible , the engraved face of the die is covered by a mask composed of some fixed oil , thickened to the consistency of a paste by the addition of animal charcoal finely powdered . This Ethiopian-like compound is spread over the surface of the engraving to which it closely adheres , filling all interstices .

As an extra precaution an iron ring is usually made to encompass tightly the matrix before hardening , so as to lessen the risk of fracture . In this condition it is deposited with its face downwards in a pot or crucible and buried once more in animal charcoal , i . e ., burnt leather , horn , & c . Tlie crucible ancl its precious contents are placed now in a furnace , the whole being heated to redness . After submission to this saturation of fire , if the term be admissible , for about an hour the pot is

withdrawn ancl the matrix , taken out of it by means of a pair of tongs is instantly and sans ceremonie plunged into a cold water bath . The bath is sufficiently capacious to contain as much water as will ' prevent the water becoming sensibly warm , by the immersion of the red hot die . Held firmly by the workman's tongs , the matrix is swayed to and fro rapidly in the water until it ceases to splutter and hiss at its rough treatment . Should no unusual or singing sound proceed from it while in

the bath , the probability is that the expansion induced by the Are , and the sudden contraction caused by the cold water have not injured the . die , and the engraver may take heart again , for his work is ' safe ancl sound . If , on the contrary , it sings , the die will be found to have cracked in the process of hardening and his work will have to be done over again . For the reasons previously given such a disastrous result seldom happens at the Royal Mint .

Allowing that all has proved favourable , the coating which protects the engraved surface is removed , ancl the matrix is forwarded to the polisher , who by pressing its "table , " or face , carefully against a flat disc of iron running rapidly in a lathe , and upon which a film of flower emery and oil has been spread , soon produces a mirror-like polish . Tempering is the next operation , for at present the steel is much too hard for its purposeand tin ' s is effected by putting the matrix into water to

, be gradually heated to the boiling point or placing it on a bar of hot iron . In either case the work is done when the die , after a series of chameleon-like changes of colour , assumes that of pale straw . At this juncture , therefore , it is again plunged into cold water , ancl the obverse matrix is ready for use . Arrangements of a precisely similar character throughout are observed in the production of the reverse matrix , and thus the first

and more important stage in the manufacture of coining dies is passed . It is time that we turned to the second block of steel , namely , that intended for the " puncheon . " This has been annealed ancl turned , not flat , but flatly conical , OH the surface to be decorated . Both it and the matrix are thus made ready for " the press , " not a printing press , but a massive ancl powerful stamping

press , with a coarse triple threaded screw of some Gin . in diameter passed vertically through its centre . Attached to theupper part of the screw , and above the press are two heavily weighted fly arms which constantly tend to force down the screw-To the lower end of the screw , and with its face downwards , the matrix is firmly fixed by a workman , who stands in a recess sunk in the floor to a depth convenient for bringing his eyes ancl his hands to a level with the bed of the press .

The puncheon block is deposited next with its face turned upwards , on the solid cast iron bed of the press , and immediately and fairly below the matrix . All being ready , several strongarmed workmen seize tbe fly arms , and walking round with them raise the screw and matrix until the latter is several inches above the puncheon block . On a sudden they release their hold andthe weihted arms revolving with a speed and force which would

g be fatal to any person standing in their way , drive down the matrix until it impinges with a dull , heavy thud upon the puncheon block . Again the workmen stand to their ( fly ) arms and raise the screw of the press . The effect of the blow is then , seen in the depressed apex of the cone-topped die which received its impact , and in the transference to itself thereby of a partial in relief of the intaglio engraved matrix . The compression

copy of the particles of steel composing the puncheon by the stress of the blow , mechanically hardens the puncheon , and before its impression can be completed by a repetition of the act , it must , be again annealed . This is effected in the same way as before . The puncheon is returned to the press , and the matrix , now de taehed from the screw , is placed loosely on the top of it , though , for an obvious reason , in such a way as that tlie engraving on

tho matrix and the partly finished impression on the puncheon , shall exactly match or fit each other . A blank block of steel is then affixed firmly by aid of set screws to the place before tenanted by the matrix , and may be saicl to represent a hammer , for it will

presently descend with great force upon the matrix , lhe fly arms are turned backward by the workmen , the . press screw is- , raised , tlie arms released , and , gathering momentum as they revolve , the hammer block is made to fall heavily ou the matrix-The effect of this second blow will , perhaps , be to make the transfer of the engraving as complete on the puncheon as is that of a seal pressed by the hand upon molten sealing wax , or it may be , if tlie steel is very obstinate , that another annealing and .

another blow may be required to effect that object . Eventually at least the puncheon will be found upon examination to have imbibed an exact ancl faithful copy in relief of the engraver ' s work on the matrix to the finest line and most minute point of detail . The duty of this latter is now done , at all events for the present , and it is placed in the engraver ' s closet . Far otherwise is ifc with the puncheon , ( or its mission is about to commence It is therefore hardened and tempered ; polished it cannot be ,

, on account of its raised surface , and then returned to the press . Such are tlie processes pursued in the making of matrices and . puncheons in reference both to coining ancl medal-striking—for . obverse and reverse , although , from the bold impressions usual on medals , many more annealings ancl sinkings of the puncheons are necessary than of those used for coin . Confining our . attention for the sake of brevity to the florin , let it now be .

presumed that puncheons for its obverse and reverse have been successfully prepared , it remains to be shown how they are put . into useful requisition , and how tbey are made the parents of rapidly-multiplying families of coining dies . Florin bars of cast , steel are about 10 ft . long , 1 Jin . broad , and 1 jin . thick ; upon these the Mint blacksmith is the first operator . One at a time they are conveyed to the forge , and out , while hot , into short , pieces of If in . in length , and in this form , therefore , resemble

Fig . 1 . These square or rectangular blocks he next proceeds to hammer into a cylindrical form , as shown in Fig . 2 . He then cuts off in a slanting direction one end of each of the die blocks , and shapes them , by way of preparation for the lathe ,, and thus they take tbe appearance depicted in Fig . 3 . Thus he proceeds with die block after die block until he has accumulated a large quantity and diminished materially the length of the bar off which they have been cut . Owing to the severe hammering to which they have been subjected , they are at this ,