[Illustration: The above diagram exposes the magic clock trick, as offered in the time of Hofrath von Eckartshausen, a German writer on magic in the eighteenth and the nineteenth centuries. Fig. 15 shows the clock in position for the trick, hung against the rear wall or "drop." Gaily-colored ribbons hide thin leather tubes through which run two sets of stout silk thread or catgut, connecting with the hour and minute hands. The thread then passes through the two iron rings, p and o in Figures 17 and 19, which are screwed to the ceiling; thence to the hidden confederate, who manipulates the clock hands as the hour and minute are announced by magician or spectator. Fig. 16 shows the two faces of the clock, with the fine connecting rod around which the string is wound to manipulate the hands. This mechanism is hidden by a flat brass band which encircles the edges of the two transparent faces. From Eckartshausen's "The Conjurer's Pocket," edition of 1791.] Years ago when I introduced this trick in my performance, I called a young man on my stage and asked him to place the hand on the spindle. It would then revolve and stop at any number named. But first I made him inform the audience the number he had chosen, which gave me time to fix the weight with my thumb. I then gave him the hand, but he was a skilled mechanic, and possibly knew the trick. Instead of holding the clock by the ring at the top, which was there for that purpose, he grasped the dial at the bottom, causing the number 6 instead of 12 to be on top. When the hand started to turn, of course it would have stopped at the wrong number. I managed to escape humiliation by pretending I was afraid he would break the clock by letting it fall, so took it away from him, holding it myself. [Illustration: Newspaper clipping of 1782, showing that Katterfelto used the cabalistic clock. From the Harry Houdini Collection.] [Illustration: Reproduction of rare engraving of Johann Nep. Hofzinser, who invented the clock worked by a counter-weight, and who was one of the world's greatest card tricksters. Original in the Harry Houdini Collection.] The mechanic walked off the stage winking at me in the most roguish manner. Robert-Houdin worked The Mystic Bell trick in connection with The Clock. This was manipulated in the same way. The bell was worked with thread, pulling a small pin, which in turn caused the handle to fall against the glass bell. Naturally, having electricity at his command at that time, he made use of that force whenever it suited his fancy.