ON TUE FINENESS OF THE ONE YEN SILVER COIN. 291 



circular discs or i; blanks " are punched out of them. A single row 

 of blanks are cut from each fillet in the case of large coins, such as 

 the silver yen. The blanks are next adjusted in weight, usually by 

 means of an automaton balance. 



After being "marked" or compressed on the edges, they are 

 annealed in iron pans, introduced into a furnace similar to that just 

 mentioned. When taken out they are cooled in water and washed in 

 very dilute sulphuric acid, by which the superficial layer of copper 

 oxide is dissolved out, leaving the blanks with a clean white surface. 

 After washing and drying, the blanks are ready fa- the coining press, 

 where they are transformed into coins. Finally the coins thus prepared 

 must lie tested as to the sound, and the correctness of weight and 

 fineness, before they are allowed to be issued to the public. 



The dimensions of the silver yen coinage bar and of the finished 

 til let are : 



Bar. Fillet 



Length. iiit.00 cm 



Breadth. 4.30 „ 5.00 cm 



Thickness. 1.25 „ 0.23 „ 



The dimensions, &c, of blank and coin are : 



One Yen Blank. One Yen Coin. 



Diameter 38.0 mm 38 mm 



Thickness 2.3 mm — 



Legal weight -116 grains, (26.957 Gram.). 



Legal tolerance in weight 1.5 „ above or below 



legal weight. 



Legal fineness 900 per mille. 



Legal tolerance in fineness 2.0 above or below 900. 



It will be seen from the preceeding account, that many other 



