Since the second edition of this book was prepared in 1949 much new material has become available, some of it covering the period before the First War, but most of it dealing with the period between the wars. The present edition brings in such material as was available up to the middle of 1957. The additional material has not required any substantial change in the nature of the book. I have, however, deleted much material from the Appendices in order to avoid making the book unwieldy.

The first edition, which was published in 1936, had two objectives. First, it was a description of the working of an important segment of the British Constitution. Secondly, it was a collection of precedents, as complete as it could be made, regulating the conventions of Cabinet government. Incidentally it fulfilled a third function, of describing the recent development of some British institutions and analysing recent constitutional disputes.

Now that the accumulated precedents of more than twenty years have been added to the Victorian and Edwardian precedents upon which the first edition was largely based, the question has arisen whether to omit some of them in order to make the book more easily read by those who desire examples rather than comprehensive information. Any such change would, I believe, make the book much less useful to the politician and the administrator.