Out of all the trees in the world, the ash is most closely bound up with who we are: the tree we have made the greatest and most varied use of over the course of human history. One frigid winter morning, Robert Penn lovingly selected an ash tree and cut it down. He wanted to see how many beautiful, handmade objects could be made from it. Thus begins an adventure of craftsmanship and discovery. Penn visits the shops of modern-day woodworkers--whose...