1967. Revised edition. 214 pages. Pictorial dust jacket over green cloth. Black and white photographs and diagrams. Pages with some foxing and tanning, particularly to endpapers and textblock edges. Binding remains firm. Dedication to front free endpaper. Boards have light shelf wear with minor corner bumping and crushing to spine ends. Unclipped jacket has light edge wear with minor tears, chipping and creasing. Some rubbing and marking to surfaces.