6o6 



THE POPULAR SCIENCE MONTHLY, 



bank-note business, as no one man can finish a note completely, 

 but must find some one to help him. 



The dies and bedpieces mentioned above are pieces of an- 

 nealed steel that is, steel that has been softened without decar- 

 bonizing on which work has been engraved that is to be used 

 several times on the same "job," or for a number of different 

 plates. These dies, after " proving," are hardened by heating in 

 cyanide of potassium, which is used in all hardening processes 

 connected with the bank-note business. After these dies are 

 hardened a roll made from very soft steel is rolled over the work 

 under a pressure of from six to twenty tons to the line. This 

 pressure is had by means of a machine called a transfer press. 



Fio. 6. Transfer Press. A, Roll in carrier; B, die or bed piece; C, foot lever ; D, rack 

 to fasten lever down ; E, side wheel by which bed of press is moved back and forth ; 

 F, rack and pinion connecting them ; G, G, fulcrum pins of upper and lower levers ; 

 il, conneotinjr rod between two levers ; I, counter balance. 



which, by a combination or compounding of levers, multiplies the 

 pressure exerted by the operator from one hundred to one hun- 

 dred and fifty times (Fig. 6). 



By means of the large wheel on the side of the press, the shaft 

 of which is geared into a rack fastened to the bed of the press, 

 the roll, with this tremendous pressure still on it, is rolled back 

 and forth on the die until the fine grain of the soft steel is forced 

 into every line of the work. This gives the reverse of the die on 



