Henry David Thoreaus Journal was his lifes work: the daily practice of writing that accompanied his daily walks, the workshop where he developed his books and essays, and a project in its own rightone of the most intensive explorations ever made of the everyday environment, the revolving seasons, and the changing self. It is a treasure trove of some of the finest prose in English and, for those acquainted with it, its prismatic pages exercise a hypnotic fascination. Yet at roughly seven thousand pages, or two million words, it remains Thoreaus least-known work.