I read Scientific American religiously as a child. Sometime around 1980, in Martin Gardner’s “Mathematical Games” column, he reprinted a woodcut from an 1893 book called Puzzles Old And New by one Professor Hoffman. The illustration showed the pieces and assembled form of what Hoffman called the “Nut” puzzle, and Gardner explained that there were many variations of this puzzle.
I was fascinated, and wanted to see how it worked. So I made one out of balsa wood, and solved it. read more...