This is volume four of the four volume set on the openings, which was the precursor of modern chess openings and encyclopedia of openings. It is a massive 696 pages in large format, 10 5/8” x 7 3/8”, and weighs almost 3 pounds. This is not the reprinted edition which sells for almost as much it has a frontispiece photograph of the author, and many diagrams. It covers mostly 1 e4 e5 openings; see the photographs. The hinges cracked between pages two and three, but the binding is sound, and there are no loose pages. There is some foxing due to age. If you watch the Queen’s gambit, the heroine used modern chess openings as her “bible”; the series of four books, preceded, and far exceeded MCO in its coverage for the time period covered.