The present collection comprises not only continuing material for Peierls's activities since 1974, but early correspondence and papers relating to his family and career. It has therefore been treated as a separate entity, with cross-references to the 1977 catalogue.

A crucial event roughly halfway through the gap between the two collections was the publication in 1986 of Peierls's memoirs, Bird of Passage. The book not only includes many references to Peierls's family, career and friends but triggered off or gave fresh impetus to correspondence from relatives and friends with family news or reminiscences, thus enriching the documentation. These are included at MS. 11619/1/A.20 and MS. 11619/44/E.78, and references to the book itself are also given in the body of the catalogue.

The material is presented as shown in the List of Contents. Additional explanatory notes are appended where appropriate to the separate sections, sub-sections and individual entries in the catalogue. The following paragraphs are intended only to draw attention to items of particular interest.

Section A, Biographical and personal, provides new material on Peierls's own career and opinions, and on his many honours and awards, but is of special interest for its family papers and correspondence, notably from Peierls's father and step-mother who remained in Berlin until 1939.

There is also some material relating to his wife Genia, including his letters to her during their long-distance courtship, written in English, German and Russian. Her influence on him, and on everyone she met, can be perceived throughout the collection, albeit indirectly. Messages for her are included in much of the correspondence during her lifetime, and many touching recollections followed her death in 1986. With the coming of war in 1939 Rudolf and Genia Peierls were anxious for their children, Gaby and Ronnie, who were evacuated to Toronto in 1940; the ensuing correspondence with their hostesses affords further glimpses of Genia's personality as well as news of the children. The lighter side of their life is shown in the verses and sketches for some of their famous parties and celebrations. Their circular letters to family and friends (MS. 11619/2/A.26-27) are invaluable in keeping track of the nomadic life they both enjoyed. A note about Genia's last illness and death is appended to MS. 11619/54/J.66.

Section B, Research and teaching, refers to work after 1974. Because of Peierls's constant travel and lack of a permanent base, much of his thinking and research was conducted by correspondence, and thus is often better documented than earlier work on ephemeral blackboards or rough paper.

Section C, Weapons control and security, expands some of the material in the previous collection, and reflects Peierls's continuing concern with the problems of international control of atomic and nuclear weapons. Foremost among the organizations he supported was the Pugwash Movement; he maintained not merely a connection but active work on its projects right up to the last weeks of his life, but, sadly, died just too soon to learn of the award of the Nobel Peace Prize for 1995 jointly to J. Rotblat and the Pugwash organization.

Section D, History of twentieth-century science and scientists, includes some original material relating to the 'Frisch-Peierls memorandum' of 1940 on the feasibility of an atomic weapon. There are also many recollections, tributes etc for leading figures in twentieth-century science, almost all drawn from Peierls's own knowledge and contacts, and including many notable German and Russian scientists. His recollections continued to be extensively called upon by writers and researchers, and published in his own frequent reviews of books and memoirs.

Section E, Publications and editorial, includes full documentation of Peierls's long service on the Editorial Board of Contemporary Physics and also of the publication of his own later books including Bird of Passage, Surprises in Theoretical Physics and its sequel More Surprises in Theoretical Physics.

Section F, Radio, television, films, is a relatively short section: most of the material606933049 relates to atomic bomb history.

Section G, Committees, societies, consultancies, is also a relatively short section, as Peierls spent so much of his retirement abroad. There is, however, material on his consultancies with the Atomic Energy Research Establishment Harwell, and the Science and Engineering Council Rutherford-Appleton Laboratory.

Section H, Seattle, and Section K, Visits, Lectures, Conferences, may be considered together as records of the constant travel which Peierls and Genia had planned and carried out for their retirement, and which continued even when, after her death in 1986, Peierls had become a solitary 'Bird of passage'.

Section J, Correspondence, and Section L, References and recommendations, relate, with few exceptions, to the post-1974 period.

Not all of the retirement correspondence is easy to read. Peierls recalls (Bird of Passage, p. 44) that his parents gave him a typewriter for his birthday in 1929 and he subsequently typed most of his own correspondence. He also recalls realising, when his translation of de Broglie's book on wave mechanism was published in 1929, that he was a negligent proof-reader (Bird of Passage, p. 41). Many of his carbon copies are in addition on somewhat poor quality paper, and fading. Later he used a succession of word-processors and sophisticated printers. By then, sadly, his eyesight had begun to fail, and this, together with his proof-reading weakness, allowed many errors to slip through which require a measure of intuition to decipher.

ADDENDA

Peierls died on 19 September 1995 when this catalogue was already prepared. Additional material thus became available at a very late date and has been dealt with in several ways.

Some items could be incorporated in the draft catalogue with no more than minor amendments of dating and indexing. This has been done wherever possible. In some cases an additional item-number was required, thus breaking the original sequence; these occur at MS. 11619/7/A.90A; MS. 11619/21/B.27A; MS. 11619/35/D.83A; MS. 11619/36/D.104A; MS. 11619/47/G.11A; MS. 11619/65/K.51A; MS. 11619/69/K.101A.

More substantial new material appears as an addendum, with explanatory note, to Sections C (MS. 11619/29/C.45-51), D (MS. 11619/39/D.135-139) and J. (MS. 11619/60/J.129-143).

We are grateful to Sir Rudolf, and his daughter, Mrs Jo Hookway, for making material available and for help in identifying some of the documents and photographs.

We thank Dr Olive Sayce for providing a translation of the item by E. Schrödinger at MS. 11619/36/D.99.