Cut out the center pip on the five-spot of spades with a sharp knife. Cut a slot centrally in another card, about 3/8in. wide and l 1/4 in. long. Glue the surfaces of both cards together near the edges to form a pocket for a slide, which is cut from another card and has one-half of its surface colored black. A drop of sealing wax attached to the back of the sliding part, so that it projects through the slot, provides a means of moving the slide in the pocket. A lightning change can be made from a five-spot to a four-spot while swinging the card.