1978. Fourth Edition. 83 pages. Illustrated dust jacket over blue cloth boards. Gilt lettering. Contains black and white illustrations and plates and folded diagrams in rear pocket. Clean pages and illustrations with light tanning and mild foxing throughout. More pronounced to free endpapers and pastedowns. Pencil and pen markings to front pastedown and free endpaper. Moderate tape marks to front pastedown and free endpaper. Pen and pencil annotations and marginalia to pages throughout. Binding remains firm. Boards have mild edge-wear with slight rubbing to surfaces and bumping to corners. Gilt lettering is bright and clear. Minor sunning to spine and edges with crushing to spine ends. Visible wear and tape marks to boards. Panels and spine have light edgewear with tears and creases. Tape marks to flaps. Visible wear marks to spine and panels.