Is that Ten-Dollar Bill Good or Bad? 



Captain Porter of the United States Secret Service 

 invents a machine which detects counterfeit money 



A good bill is placed on one of the oblong metal plates nnd the 

 suspected counterfeit on the other so that the various orna- 

 ments on the two may be compared according to squares 



A NEWEST aid to the prevention of 

 counterfeiting is a contrivance re- 

 cently invented by Capt. Thomas 

 I. Porter, head of the Chicago office of 

 the United States Secret Service. His 

 machine is especially intended to detect 

 counterfeit bills or coins at the moment the 

 possessor attempts to pass them at a bank. 

 Through the aid of modern processes of 

 printing and engraving counterfeits can be 

 made so much like originals that they defy 

 ordinary inspection. A special machine is 

 necessary. 



Captain Porter's contrivance depends on 

 the principle that a counterfeiter rarely suc- 

 ceeds in making perfect original plates for 

 his bills. Somehow or other there is always 

 I slight distortion in some part. To the 

 casual eye the products of the counterfeiter 

 look exactly like those of Uncle Sam. But 

 most plate-engraving processes make use 

 of photography at one stage or another. 

 The images of the bills must pass through a 

 lens, which passage is sure to distort them. 

 Though the distortion is slight, minute 

 comparison with a good bill reveals the de- 

 fects. The new machine is designed to 

 make the work of comparison easy. 



The detector 

 consists simply of 

 a thick wooden 

 frame about ten inches 

 or a foot square. On the top surface, brass 

 edgings are provided which hold in place a 

 large plate of glass — this being divided into 

 squares about one-fourth of an inch apart. 

 Several glass plates are provided, each with 

 a different set of rulings suited to the fine- 

 ness of the bill undergoing test. Beneath 

 the glass plate are tvvo thin oblong metal 

 plates faced on their upper surfaces with 

 blotting paper or other material having a 

 rough surface to which a bill will readily 

 adhere. These metal plates rest side by 

 side beneath the glass and are provided 

 with handles at each end extending be- 

 yond the glass. By means of the handles 

 the bills may be shifted around under the 

 glass at will. 



In using the machine, a good bill is 

 placed on one of the oblong metal plates, 

 and the supposed counterfeit on the other — 

 each adhering to the blotting-paper upF>er 

 surface of its respective plate. The ruled 

 glass is then placed down over the metal 

 plates and their accompanying bills, and 



