When a tree is felled, its green wood is wet and easy to work with simple hand tools. As the wood dries it becomes hard and difficult. Old timers would shape chair parts from green wood cut from a small tree nearby, assemble them without nails, and as the wood dried it would shrink into a tight, strong, beautiful chair. This lost art was rediscovered by the author of this book, John Alexander. But now the book itself is long out of print, and used copies go for $350.
In the 35 years since the first edition of the book, the author has kept refining his process (while undergoing a gender change; John is now Jennie) and has produced a video of her highly refined process. In many ways the video is even better than the book. Sample excerpts of the video can be seen here. Alexander promises a third edition of the book.
If the idea of making a chair from a tree interest you, the Greenwoodworking website is worth checking out.