Fig. 21.
The problem is to slide the middle piece off of the pin that projects up from the lower piece and swing it around its pivot. This pivot is a 1-1/2" round-headed screw, fitting loosely in the upper two and fixed in the lower piece. A 1/2" hole is bored thru the middle and 1/2" deep in the upper piece to hold the 7/16" ball. This hole is bored so it touches the hole for the screw. In the middle piece, the screw can slide into it. In order to make the ball leave its position in the middle piece, the puzzle must be held upside down. The drawings show the puzzle both closed and open, and supply directions for constructing this interesting problem.
Finish with stain and two coats of shellac. This puzzle may be a source of much genuine amusement when a circle of friends come together and all want a hand at opening it, each having his advice to give how to solve this mysterious problem.
Ball Puzzle
