Potentially a permanent fixture in the homes of puzzle enthusiasts, this challenging pastime consists of a solid-backed oak frame and 14 oak pieces of varying sizes and shapes that slide around within it.One of the pieces is narrower than the others and can easily slip through a slot located in the lower, right-hand corner of the frame.Far less easy is maneuvering the Chosen Piece there.The object of the puzzle--of which there are a dozen variations of increasing complexity (43 moves for the first, 263 moves for the last!)--is to deduce which pieces need to slide where so that the logical route for the thin piece reveals itself.If you just can't figure some of the puzzlers out, solutions are available for $5 through a California address.--Tom Keogh