Diabolical cube seven and nine pieces respectively. However, writes that the diabolical cube appears to be the oldest puzzle of this type, first appearing in an 1893 book "Puzzles Old and New" by Professor Hoffmann (Angelo Lewis). Because all of the pieces have only a single layer of cubes, their shape is unchanged by a mirror reflection, so a mirror reflection of a solution produces either the same solution or another valid solution. The puzzle has 13 different solutions, if mirrored pairs of solutions are not counted as being distinct from each other. Diabolical cube The diabolical cube is a three-dimensional dissection
Helicopter Cube corner pieces and 24 face center pieces. Each corner piece has 3 colors, and each face center piece has only a single color. Unlike the Rubik's Cube, its faces do not rotate; rather, the pieces are scrambled by rotating around a cube edge. When twisting the puzzle, a 180° turn exchanges two corner pieces and swaps two pairs of face center pieces, but preserves the cube shape. The entire puzzle can be scrambled in this way. However, it is also possible to twist an edge by ~71°, such that the base of two groups of a corner piece and a