Fifteen Puzzle: the little box that conquered the world
In the late 19th century, American newspapers wrote about people sliding tiles in a little box right at lunch. Conductors, clerks, bakers — everyone pushed numbered pieces into the free corner.
A box for a couple of cents
It sold as a cheap pastime: a 4x4 field, fifteen numbered tiles, one cell empty. A single move — slide a neighbouring tile into the gap. The goal — line up 1 to 15 with the empty cell at the bottom right. Fewer rules than fingers on a hand. But cities caught the fever: tournaments, prizes for solving rare layouts.
The trick with the top row
I pushed tiles at random for a long time until I tried solving row by row. Top row left to right, then the second. The bottom two rows go in pairs: two tiles take their places by circling around. The shuffle button here is honest — the layout is always solvable, so there is nobody to blame.
Why the little box is still alive
The mechanic never aged: an empty cell and fifteen tiles give the same fiddling as a hundred years ago. Click a tile next to the gap and it slides. Line up 1–15 in order and the board stands straight.