1968. Nineteenth Edition. 128 pages. Illustrated dust jacket over red cloth covered boards. Pages remain clear with minimal tanning and foxing, mild to end-papers and text-block edges. Minor pencil marking to front free end-paper. Some occasional mild cracking to gutters throughout, binding remains reasonably firm. Boards have moderate edge-wear with bumping to corners and rubbing to surfaces. Mild crushing to spine ends. Book has a slight forward lean. Clipped jacket has moderate edge-wear with chips, tears and creasing.