1928. 232 pages. No dust jacket. This is an ex-Library book. Green decorative cloth with gilt lettering. Contains black and white diagrams. Expected library inserts, stamps and inscriptions. Mild tanning to endpapers. Mild tanning to pages throughout with occasional light foxing and thumb marking present. Moderate foxing to text block edges. Boards have mild shelf wear with light rubbing and corner bumping. Some light marking and tanning to spine with crushing at ends.