1973. Twentieth Edition. 349 pages. No dust jacket. Illustrated paper covered boards. Black and white photographic images. Light staining, foxing and tanning to pages. More prominent to text block edges, pastedowns and free endpapers. Light cracking and staining to gutters and hinges but binding remains firm. Boards have minor corner bumping and edgewear with mild sunning and scuffing overall. Spine has similar sunning with soft crushing to ends.