1968. Third edition. 199 pages. No dust jacket. This is an ex-Library book. Pictorial cloth covered boards. Black and white photographs and diagrams. Ex library copy with associated labels, inserts, stamps and annotations. Pages remain bright and clean with minimal tanning and foxing. Binding remains firm. Boards have mild shelf wear with light rubbing and corner bumping. Some moderate marking and tanning. Boards are slightly bowed.