Eleventh edition. 492pp, with several pages of publisher's adverts at rear, black and white plate frontispiece, with occasional illustrations and figures in text. Green cloth-covered boards with black lettering on the front panel, gilt titles on spine. Decorative endpapers. 12mo. Cloth rubbed and rounded at corners and spine ends, a few mild marks. Upper text block edge dust darkened, remaining edges spotted. Some tanning on endpapers else internally neat and clean. Slight forward lean.