1949. Second Edition 1949. 284 pages. No dust jacket. Green cloth boards with lettering. Contains folded diagrams. Slight crinkling to gutters however binding remains firm. Pages remain clear with minimal tanning and foxing. Heavier tanning and foxing to pastedowns and free endpapers. Boards have moderate edge-wear with bumping to corners and rubbing to surfaces. Heavy water and brown marks to boards and spine. Lettering is bright and clear. Boards are slightly bowed.