1961. 11th edition. 155 pages. Blue dust jacket over blue cloth and blue lettering. Contains black and white illustrations. Binding remains firm.Pages and illustrations remain bright with minimal tanning. More pronounced tanning and foxing to free end papers and pastedowns. Boards have light edge-wear with slight rubbing to surfaces.Mild crushing to spine ends causing cloth to fray. Corners are slightly bumped. Unclipped jacket. Moderate tanning to jacket spine and edges. Jacket has light edge-wear with closed tears and creasing.