1968. First Edition. 111 pages. Signed by the author. Photographic dust jacket over blue cloth. Black and white illustrations and graphs throughout. Light tanning to pages with creasing to gutters and hinges. Binding remains firm. Pen inscription to front free endpaper. Boards have minor corner bumping and edgewear. Spine has light tanning with soft crushing to ends. Unclipped dust jacket with moderate tanning and scuffing overall.