The seven-ring puzzle is, as already stated, the simplest of these puzzles, as the ten-ring puzzle is usually the most complicated. To perform the ten-ring puzzle it has been computed requires no less than 681 moves. The instructions given above apply equally well to both, if only the note as to an odd or even number of rings to be removed is remembered.
The puzzle of the Balls and Rings (Fig. 12) has points of similarity with the above, and also with that of the string and balls puzzle. The balls and rings puzzle is very ingenious, and should be asked for at the toy-shop. It consists of a round frame of mahogany, about two inches in width and a quarter of an inch thick. In this frame, and at regular intervals, are holes, between which are placed, on the one side of the frame, rings, and on the other side, balls. The rings and balls are made fast with a cord, which passes through each ring and each ball, and also through all the holes in the frame, the ends of the cord being tied in a cross. The puzzle is to reverse the position of both the rings and the balls from one side of the frame to the other.
Fig. 12.—Balls and Rings Puzzle.—a, Plan; b, Side View.
As indicated in the String and Balls puzzle, the key to this and similar puzzles is to be found in a loop of string, which is usually concealed in some part of the puzzle. The loop should be pulled out or through the wood, and passed over the ball nearest to it; the solution of the puzzle will then be apparent.
THE STAFF PUZZLE, THE VICTORIA PUZZLE, AND THE ARTILLERY PUZZLE.
These are all ingenious puzzles of this class, introduced by Mr. Cremer, of Regent Street, who issues the keys for the solution of the puzzles with the toys.
THE SIX ROWS PUZZLE.
Place twelve counters in six rows in such a manner that there shall be four counters in each row. Fig. 13 shows how the puzzle is solved.
