This book is an extensively researched masterpiece which goes into great depth about the Fifteen Puzzle craze that swept 19th century America. I was shocked to discover that Sam Loyd lied when he claimed he invented the impossible 14-15 Puzzle, and he wasn't even the first to offer a prize for solving it either! That honor goes to dentist Charles Pevey who bizarrely offered a $25. set of teeth. The book contains many more fascinating insights like this and is a must for any puzzle lover.