1938. Thirteenth Edition. 299 pages. No dust jacket. Blue cloth covered boards. Black and white diagrams and folded charts throughout. Pages with some foxing and tanning, particularly to endpapers and textblock edges. Binding remains firm. Boards have heavy shelf wear with bumping and fraying to corners and crushing and fraying to spine ends. All surfaces heavily tanned. Gilt lettering to spine is slightly dulled. Some additional marks and staining to surfaces.