base onto the inked slab; then lifted it and pressed it onto the back of a visiting-card, and again raised it; and now the card was marked by a very distinct thumb-print.
"My God!" exclaimed the detective, picking up the card and viewing it with a stare of dismay, "this is the very devil, sir. This fairly knocks the bottom out of finger-print identification. May I ask, sir, how you made that stamp—for I suppose you did make it?"
"Yes, we made it here, and the process we used was practically that used by photo-engravers in making line blocks; that is to say, we photographed one of Mr. Hornby's thumb-prints, printed it on a plate of chrome-gelatine, developed the plate with hot water and this"—here he touched the embossed surface of the stamp—"is what remained. But we could have done it in various other ways; for instance, with common transfer paper and lithographic stone; indeed, I assure you, Miller, that there is nothing easier to forge than a finger-print, and it can be done with such perfection that the forger himself cannot tell his own forgery from a genuine original, even when they are placed side by side."
"Well, I'm hanged," grunted the superintendent, "you've fairly knocked me, this time, doctor." He rose gloomily and prepared to depart. "I suppose," he added, "your interest
