1957. Twenty-Third Edition. 1597 pages. No dust jacket. Orange cloth. Clean pages with notable tanning and visible foxing throughout. Tightly bound with faint thumb-marking throughout. Notable droplet staining to text block edges. Boards have light edgewear with corner crushing and notable marking to boards. Notable tanning to board edges and spine. Mild scuffing to joints. Sticker to rear board. Book has forward lean. Boards are mildly warped.