Needle thru Brass Block (0404-w4)

Hand the spectator a small match box with a tiny hole going through it, and also a needle with a ribbon threaded through it. You push the needle and ribbon several times through the hole in the middle. He is now instructed to push the needle through the box, and pull the ribbon through. But he cannot do it; upon opening the box, it is found to contain a SOLID BLOCK OF BRASS! An amazing trick!