1968. Fourth Edition, Reprinted. 320 pages. Illustrated dust jacket over blue cloth covered boards with gilt. Pages remain clear with minimal tanning and foxing. Cracking to hinges, no damage to end papers. Some occasional moderate cracking to gutters throughout, binding remains reasonably firm. Boards have mild edge-wear with slight rubbing to surfaces. Mild crushing to spine ends. Book has a slight forward lean. Boards have minor damp and dust stains. Book has a slight forward lean. Unclipped jacket has moderate edge-wear with chips, tears and creasing.