Equilibrium, also known as "Equi-librium" is an interlocking puzzle in the shape of a sphere. Copyrighted in 1974 by Reiss Games, Inc., it consists of 6 closed arch pieces, 5 of which have pegs on their straight center. The two pegs block the other pieces from being shifted back or forth, only the sixth piece is different having only one peg and two notches. These notches are above and below where the peg would be located on the other pieces, allowing only this notched piece to be moved at first. When it is moved so the notch fits over another piece's peg, the two pegged piece can be moved. Once a two peg piece has been slid to the side, the notched piece can be moved to its second notch and lifted off. Once the notch piece is removed, all the others become loose and the puzzle usually crumbles into its remaining pieces. The challenge is to put it back together. Equilibrium was sold in a cardboard box, with a solution sheet enclosed.

• "It looks tranquilizing till you take it... apart, that is. But getting this well-designed sphere (and you) back together again won't be easy."

The secret in putting it back together involves not only holding the pieces in such a way that all three angles are supported so they can hold the others, but also knowing how to place the 'Key' or notched piece to lock it all together. A later colored version named "Sphere" was released by Net Block.

Solution

Saving the notched piece until last, set two pieces so they are facing away from each other, such as db, then place another between them at a 45 degree angle in a U shape. This will make the bottom of the sphere and serve as a platform for the other pieces. Rest the pieces on the middle finger to give them a firm base, with the thumb and first finger reaching through the U shaped piece so that the two db pieces can be held. Using the U shaped pieces as a table place two other pieces on either side of it, they will curve towards each other so that they hold the db pieces up, they will link together so that it won't be as wobbly. Then the notched piece should be slide down from the top, but it'll be stopped by two pegs. The notched piece will now give the side pieces a brace so they don't fall inward. The notched piece should be slid in so the first notch near the edge will meet the two pegs below it, push it onto the pegs, if done carefully this will cause one of the pegged pieces to sink down, as the first peg clears the center beam, move it more towards the center of the sphere, so the second notch is over the second peg. Slide the pegged piece back upward, now only the notched piece will be out of place. To lock the pegged piece into place push the notched piece to its center position.

See also

• Rubik's Cube
  Rubik's Cube
  Rubik's Cube is a 3-D mechanical puzzle invented in 1974 by Hungarian sculptor and professor of architecture Ernő Rubik.Originally called the "Magic Cube", the puzzle was licensed by Rubik to be sold by Ideal Toy Corp. in 1980 and won the German Game of the Year special award for Best Puzzle that...
  
  
• Alexander's Star
  Alexander's Star
  Alexander's Star is a puzzle similar to the Rubik's Cube, in the shape of a great dodecahedron.-History:Alexander's Star was invented by Adam Alexander, an American mathematician, in 1982...
  
  
• Pyraminx
  Pyraminx
  The Pyraminx is a tetrahedral puzzle similar to the Rubik's Cube. It was invented and patented by Uwe Meffert, and introduced by Tomy Toys of Japan in 1981. Meffert continues to sell it in his toy shop, ....
  
  
• Pyramorphix
  Pyramorphix
  The Pyramorphix is a tetrahedral puzzle similar to the Rubik's Cube. It has a total of 8 movable pieces to rearrange, compared to the 20 of the Rubik's cube. Though it looks like a simpler version of the Pyraminx, it is an edge-turning puzzle with the mechanism identical to that of the Pocket...
  
  
• Skewb
  Skewb
  The Skewb is a combination puzzle- a mechanical puzzle in the style of Rubik's Cube—invented by Tony Durham and marketed by Uwe Mèffert. Although it is cubical in shape, it differs from Rubik's construction in that its axes of rotation pass through the corners of the cube rather than the centres of...
  
  
• Skewb Diamond
  Skewb Diamond
  The Skewb Diamond is an octahedron-shaped puzzle similar to the Rubik's Cube. It has 14 movable pieces which can be rearranged in a total of 138,240 possible combinations. This puzzle is the dual polyhedron of the Skewb.- Description :...
  
  
• Skewb Ultimate
  Skewb Ultimate
  The Skewb Ultimate, originally marketed as Pyraminx Ball is a twelve-sided puzzle derivation of the Skewb, produced by famous toy-maker Uwe Meffert...
  
  
• Megaminx
  Megaminx
  The Megaminx is a dodecahedron-shaped puzzle similar to the Rubik's Cube. It has a total of 50 movable pieces to rearrange, compared to the 20 movable pieces of the Rubik's cube.- History :...
  
  
• Dogic
  Dogic
  The Dogic is an icosahedron-shaped puzzle like the Rubik's cube. The 5 triangles meeting at its tips may be rotated, or 5 entire faces around the tip may be rotated. It has a total of 80 movable pieces to rearrange, compared to the 20 pieces in the Rubik's cube.- History :The Dogic was patented by...
  
  
• Burr puzzle
  Burr puzzle
  Burr puzzles are interlocking puzzles known in Europe and Asia since at least the 18th century. Traditionally they are made from wood, but some modern versions use plastic while those of collector's quality may be made from brass...