1961. Revised Edition. 170 pages. Pictorial dust jacket over blue cloth. Black and white photographs and diagrams. Pictorial endpapers. Pages remain bright and clean with minimal tanning and foxing. Binding remains firm. 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 scuff marking to surfaces. Spine noticeably sunned.