1956. Seventh Revised Edition. 144 pages. Illustrated dust jacket over blue cloth covered boards with gilt. Filled with black and white photos. Pages remain clear with minimal tanning and foxing. Binding remains firm. Boards have mild edge-wear with slight rubbing to surfaces. Mild crushing to spine ends. Gilt lettering has become dull. Book has a slight forward lean. Unclipped jacket has heavy edge-wear with some areas of loss, heavy tears, chips and creasing.