Minting in 

 Miniature 



By Oscar Lewis 



IN one corner of the great exhibit 

 palace sheltering the Departments of 

 Mines and Metallurgy at the Panama- 

 Pacific Exposition, there is to be found 

 one of the most interesting of the United 

 States Government exhibits. It is part 

 of the display of the Treasury Depart- 

 ment and consists of a miniature mint 

 that is complete in every detail. There 

 one may see and have explained to him 

 each successive step in the minting of the 

 Government coins, from the time that 

 the bars of impure metal are refined by 

 the new electrolytic process until the 

 shining new coins pass the final inspec- 

 tion and are ready to go out into circu- 

 lation. 



To one who has never before witnessed 

 the process, the various steps that are 

 gone through in the minting of a coin are 

 interesting. The metal, when it reaches 

 the mint, is in an impure state and after 

 being refined by means of the electric 

 current in the new "electrolytic," as the 

 machine is called, the pure metal is 

 melted in an electric furnace and mixed 

 with its alloy. Both gold and silver in 

 their pure state are very soft, and a 

 small amount of some harder metal must 

 be added to them so that the completed 

 coin will be hard enough to resist the 

 wear that it will be subjected to when 

 placed in circulation. 



After the alloy has been added the 

 crucible is tilted and the molten metal 

 poured into moulds. After a moment 

 these moulds are removed and the metal 

 bar is cooled before being run through 

 the rolling machine. The size of the in- 

 gots into which the metal is cast depends 

 upon the denomination of the coins to be 

 made from them. For double eagles, the 

 largest gold piece that the Government 



mints, the ingot is slightly over a foot 

 long by one and one-half inches wide 

 and a half inch thick, and has a valua- 

 tion of $1,488. 



After passing several times through 

 the rolling machines the bars are greatly 

 lengthened, coming out finally over four 

 feet long, while in thickness they have 

 been reduced to seven-sixteenths of an 

 inch slightly thicker than the finished 

 coin. 



The strips of metal are now ready for 

 delivery to the next machine where an- 

 other important step in its transition from 

 the ingot to the coin takes place. This 

 is the automatic cutting press that grasps 

 the strips as they are fed into the machine 

 and draws them under a steel punch 

 which, at the rate of eighty a minute, 

 stamps out the .round coin blanks or 

 "plankets," as they are called. These 

 plankets are slightly smaller and thicker 

 than the completed coins. The perfor- 

 ated strips are sent back to be melted 

 over again, while the coin blanks are in- 

 spected and weighed and then passed on 

 to the "upsetting machine" for the next 

 process. 



In the upsetting machine the blanks 

 are caught between two high pressure 

 stamps which raise, or "upset," the outer 

 protecting ridge on the edges of the coin, 

 the purpose of which is to make the com- 

 pleted coins "stack" properly, and also 

 to protect the impression on the face 

 from wear. 



The blanks are now heated, cleaned and 

 dried each process being carried on in 

 a special machine and are once more 

 inspected before the actual striking of the 

 impression on the coin takes place. The 

 coining press is large and massive in con- 

 struction. The oval-shaped frame is 



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