Look closely at the United States notes, the fractional currency bonds, and the most valuable revenue stamps, and you will see many lines involved and intricate, running to and fro in the most marvellous manner. These lines defy imitation. They are the best tantalizer and detective of the most accurate counterfeiter. The most absolute imitation, made by hand, can be instantly perceived under a glass. These involuting lines are the work of the geometric lathe, an instrument whose complicated wheels can be set to work out any combination of curved lines which the human mind can possibly conceive. The counterfeiter, with the same lathe, would be powerless to produce the same complications—“he would grow gray in endless and useless experiments, and even with a record of the combination, he could not so exactly re-produce it, that an expert could not detect the imposition.” The geometric lathe of the Treasury of the United States, is worked by Mr. Tichenor, who has been a skilled artist in such machinery for more than thirty years. There are no more interesting objects in the Treasury, than the line of clear-eyed men who sit bent over their tasks, their subtle lines tracing the exquisite vignettes which have made the engravings of the United States Treasury so famous. Here is one who has been tracing these lines of beauty for more than forty years: his hair is white, but his keen, strong sight—drawing harmony, poetry, nature, and life, out of barest outline—remains undimmed. CHAPTER XXXI. THE WORKERS IN THE TREASURY—HOW THE MONEY IS MADE.