by J. H. Thomas and D. E. B. Powell; with a foreword by W. Ferguson Anderson. by O. S. Puckle and J. R. Arrowsmith. With a foreword by Sir Willis Jackson. by B. Randell and L. J. Russell. With a foreword by E. W. Dijkstra. John H. Dodds and Lorin W. Roberts ; foreword by J. Heslop-Harrison. by R. C. Brimley and F. C. Barrett. With a foreword by E. C. Bate-Smith.