1949. First Edition. 104 pages. Pictorial dust jacket over yellow cloth. Black and white diagrams throughout. Pages with some foxing and tanning, particularly to endpapers and textblock edges. Binding remains firm. Some page corners folded. Small bookshop label to front pastedown. Boards have light shelf wear with minor corner bumping and crushing to spine ends. Clipped jacket has light edge wear with minor tears, chipping and creasing. Some tanning and foxing to all surfaces, particularly to spine.