1975, New & Revised Edition, Bibliography, Index, 383 Pages, This Is A Very Good Copy In The Original Orange Cloth Covers, With The Title In Gilt On The Spine, Complete With The Illustrated Dustwrapper. This Edition Contains The Haughley Experiment, Which Is Not In The Earlier Editions. The Fact That It Was A Unique Piece Of Fundamental Research That Has Come To An End After This 25 Years Record Of Its Development And Findings Scientifically Important For The Future. Fine Reference.