Larry D. Nichols Larry D. Nichols Larry D. Nichols, born 1939 in the United States, is a puzzle designer. He grew up in Xenia, Ohio, and studied chemistry at DePauw University in Greencastle, Indiana, before moving to Massachusetts to attend Harvard Graduate School. He is best known for the invention of mechanical puzzles including 'The Nichols Cube Puzzle' (1974), patent US365520. He has lived with his wife Karen in Arlington, Massachusetts since 1959. In 1957, 17 years before Dr. Rubik’s invention popularly known as the “Rubik's Cube”, Dr. Nichols conceived of a twist cube puzzle with six colored faces. It was a 2×2×2
15 puzzle 15 puzzle The 15-puzzle (also called Gem Puzzle, Boss Puzzle, Game of Fifteen, Mystic Square and many others) is a sliding puzzle that consists of a frame of numbered square tiles in random order with one tile missing. The puzzle also exists in other sizes, particularly the smaller 8-puzzle. If the size is 3×3 tiles, the puzzle is called the 8-puzzle or 9-puzzle, and if 4×4 tiles, the puzzle is called the 15-puzzle or 16-puzzle named, respectively, for the number of tiles and the number of spaces. The object of the puzzle is to place the tiles in order by