1951. First Edition. 320 pages. No dust jacket. This is an ex-Library book. Black cloth covered boards. Black and white diagrams throughout. Ex library copy with associated labels, inserts, stamps and annotations. Pages remain bright and clean with minimal tanning. Slight cracking to front hinge with netting exposed. Binding slightly slack. Boards have heavy shelf wear with bumping and fraying to corners, crushing to spine ends and rubbing and staining all over. Spine has a library number with tape. Book has slight forward lean.