1949. Reprinted. 82 pages. Pictorial dust jacket over blue cloth. Black and white diagrams throughout. Pages with some foxing and tanning, particularly to endpapers and textblock edges. 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 chipping and creasing. Some tanning and foxing to all surfaces, particularly to spine.