In the late 19th century this puzzle drove the entire world crazy. When Sam Loyd introduced the game to the public in 1878 he used a trick to arouse interest for it - he offered a thousand dollars to the one who could solve it. The puzzle consisted of a little box with 15 numbered square pieces that could be slid around to be arranged in rows from 1 in the upper left corner to 15 last on the bottom row.But then only the last two tiles 14 and...