THE reprinting of this book makes it possible to say a few things which should have been said before. The book would never have appeared at all but for the admirable work of Mr. Johnstone-Wilson of the British Museum, who corrected the proofs and checked or supplied a number of references during very difficult times: it owes a great deal to the advice and criticism of Mr. John Sparrow and Mr. D. P. Walker.
The first completed typescript went to America and never came back. An imperfect carbon copy was completed and corrected without reference books, in odd moments 'after duty'; and from this the text was set up. Chapters I and VII badly need rearrangement, but for many reasons, both on the publishers' side and on my own, it has not been possible to make any major alterations: a few slips have been put right, a few sentences re-shaped, and a note has been added or altered here and there to make a point clearer. Otherwise the text must stand with no addition but my thanks for the generosity with which friends improved and strangers received it.
IN THE FIELD