1932. Sixth Edition. 151 pages. Brown dust jacket over blue cloth boards with gilt lettering to spine and front. Black and white tables & charts as well as illustrative and photographic plates throughout. Binding loose. Pages are moderately tanned throughout. Previous owner's inscription to front endpaper. Cracking to gutters, with exposed netting. Boards have mild edge wear with slight rubbing to surfaces. There is bumping to corners and crushing to spine ends. Tanning to spine and edges. Gilt lettering is bright and clear. Book has a slight forward lean. Unclipped jacket has heavy edge wear with some areas of loss, heavy chips, tears and creasing. Tanning to spine and edges causing discolouration.