|Material||:||Ebony, Piqua Amarello & Sterling Silver|
The objective is to remove the chain. The balls at either end of the rod turn freely.
One of the balls will unscrew at the second grove allowing the chain to be slipped over the end. To unscrew it, you must hold the rod in one hand, pressing the small part of the ball against the rod so it will not turn. The drawing is from Professor Hoffmann's Puzzles Old & New, 1893.