Undated. xii, 192pp (including xii of answers), various black and white diagrams. Maroon cloth-covered board,; black titles on front and spine. 12mo. Mottling and wear to boards, rubbed corners and spine ends, cupped and cocked. Top text block edge dusty, remaining edges starting to tan and fox. Volume quite loose. Endpapers tanned. Internally neat, clean and bright.