1931. No Edition Remarks. 160 pages. No dust jacket. This is an ex-Library book. Red cloth covered boards. Black and white diagrams throughout. Pages with some foxing and tanning, particularly to endpapers and textblock edges. Binding remains firm. Minor pencil inscriptions to front free endpaper. Boards have moderate shelf wear with mild bumping and fraying to corners and crushing and fraying to spine ends. All surfaces tanned and sunned, particularly spine. Gilt lettering is dulled. Boards are slightly bowed.