1917. Fourth Impression. 334 pages. No dust jacket. Green cloth with gilt lettering. Black and white graphs and diagrams throughout. Light tanning to pages with light cracking to gutters; binding otherwise remains firm. Pen inscriptions to front pastedown and half title page. Boards have minor corner bumping, denting and edgewear with mild scuffing overall. Spine has light tanning with soft crushing to ends. Lettering remains bright and clear. Book has a slight forward lean.