1947. Eleventh edition. 216 pages. No dust jacket. Green cloth covered boards. Black and white diagrams throughout. Pages with some foxing and tanning, particularly to endpapers and textblock edges. Binding remains firm. A previous owner's name to front free endpaper. Pencil inscriptions to rear free endpaper. Boards have light shelf wear with minor corner bumping and crushing to spine ends. Some mild marks and staining to surfaces.