of Dies for Medals and Coinage. 117 



ing an uniform textnre, when its surface is washed over with a 

 little aqua-fortis, by which its freedom from pins of iron, and 

 other irregularities of composition, is sufficiently indicated. 



The best kind of steel being thus selected, and properly 

 forged* into the rough die, it is softened by very careful ai- 

 nealing, and in that state, having been smoothed externally, 

 and brought to a table in the turning lathe, it is delivered to the 

 engraver. 



The process of annealing the die consists in heating it to a 

 bright cherry red, and suffering it to cool gradually, which is 

 best effected by bedding it in a crucible or iron pot of coarsely- 

 poAvdered charcoal, that of animal substances being generally 

 preferred. In this operation it is sometimes supposed that thfe 

 die, or at least its superficial parts, becomes super-carbonized, 

 or highly-converted, steel, as it is sometimes called ; but expe- 

 rience does not justify such an opinion, and I believe the com- 

 2)Osition of the die is scarcely, certainly not materially, affected 

 by the process, for it does not remain long enough in the fire 

 for the purpose. 



The engi-aver usually commence* his labours by working out 

 the device with small steel tools, in intaglio ; he rarely begins 

 in relief (though this is sometimes done) ; and having \dti- 

 mately completed his design, and satisfied himself of its 

 general effect and correctness, by impressions in clay, and 

 dabs, or casts.f in soft metal, the die is ready for the important 

 operation of hardening, which, from various causes, a few of 

 which I shall enumerate, is a process of much risk and diffi- 

 culty ; for should any accident now occur, the labour of many 

 months may be seriously injured, or even rendered quite 

 useless. 



The process of hardening soft steel is in itself very simple, 



♦ The art of forgins: dies requires much practice and experience, not 

 only as to tlie choice of steel, but as to the manual part of the operation. 

 They should be forced at a high heat, and great care should be taken to 

 give a perfect and dense texture to the upper part of the die. 



t T\T3e metal is usually employed for this purpose. The die is warmed, 

 and placed in a convenient box, in which the melted metal may be 

 splashed, or dabbed, upon it. The impression is often extremely clear 

 and perfect, and exceeds in effect those which are taken in wax or 

 plaistcr. 



