1954. Fourth Edition. 207 pages. No dust jacket. Brown cloth boards with gilt lettering. Contains black and white illustrations and folded diagrams. Clean pages and illustrations with light tanning and mild foxing throughout. More pronounced to free endpapers and pastedowns. Binding remains firm. Boards have mild edge-wear with slight rubbing to surfaces and bumping to corners. Gilt lettering is darkened. Moderate sunning to spine and edges with crushing to spine ends. Minor splits to spine ends and corners causing cloth to be frayed. Visible wear marks to boards.