Wallace Stegner called its stacks "enchanted." Barbara Tuchman called it "my Archimedes bathtub, my burning bush." But to Thomas Wolfe, it was a place of "wilderment and despair." Since its opening in 1915, the Harry Elkins Widener Memorial Library has led a spirited life as Harvard's physical and, in a sense, its spiritual heart. Originally intended as the memorial to one man, it quickly grew into a symbol of the life of the mind with few equals...