1928. Fourth edition. 816 pages. No dust jacket. Green cloth with gilt titles to spine. Volume I. Includes various diagrams. Revised by W D Lang. Pages have slight foxing, tanning and minor thumbing. Previous owner's inscription to front endpaper and pastedown. Foxing more noticeable towards the start and end of the book. A few dog-eared corners. Text block edges are heavily tanned. Boards have heavy edge wear, with bumping and fraying to corners, while spine ends are crushed and frayed. Joints worn too with splits starting. Scratched, rubbed and marked overall. A few ring marks to front board, plus some minor dents. Gilt is bright.