Walter Ledermann - Encounters of a Mathematician

Sussex: 1962-97

Moving to the new university.

To join the new University of Sussex was both an exciting and a challenging experience. The first question was: where to stay? Some of my senior colleagues said: "Do not live in Brighton. It is vulgar. Lewes is a more appropriate place." I did not like to go to Lewes because I am fond of the sea. But I remembered meeting Mr Arthur Block, a nice old gentleman. He was a member of the Council of the Haifa Technion and had come to Manchester to form a Technion Society in support of Israel's leading Institute of Technology. He asked me to be the Secretary of this Society, a task which I was very willing to carry out. In fact, there was a Technion Society in Manchester before there was a similar Society in London. Mr Block told me that he was living at Rottingdean, a charming place by the sea on the outskirts of Brighton. Looking at a local map I noticed that there was a road that started from Rottingdean, went across the Sussex Downs and ended directly in front of the Campus of the University. So it would be very easy for me to go to work by car without having to pass through any built-up areas. We found a suitable house at 1, Lenham Road East, Rottingdean and moved into it in the summer of 1962. A few alterations had to be made; in particular, the outside of the balcony had to be repainted, for which Jonathan, then aged 8, designed the colour scheme.

The University had started the previous year in 1961, before the campus was ready and only Arts subjects were being taught in rented premises at Brighton. The opening of the campus at Falmer was celebrated on a fine autumn day in 1962. We went to a magnificent party held on the lawn. Delicious refreshments were being served; there was a complete pig being roasted on a spit. It was a very friendly atmosphere.
The idea of Sussex University.

The University of Sussex differed markedly in most respects from the universities with which I had been connected as a teacher or as a student. On the educational side the principal idea was that subjects should not be taught in isolation. Narrow specialization was rejected in favour of interdisciplinary studies. Thus the word "department" was banned and replaced by "Schools of Studies." I think the idea is perhaps more relevant in the Arts subjects than in Science. For example when studying Italian literature it is helpful to be acquainted with the history, social condition, philosophy and religion of that country. To be sure there are also important cross connections in the Sciences. But quite often they work in an unsymmetrical way: a competent chemist, especially if he works on the theoretical aspects, has to have a thorough knowledge of physics; a physicist, especially if he works on the theoretical aspect of his subject, has to have a thorough knowledge of mathematics. But for many topics in physics no detailed knowledge of chemistry is needed, and one can be a very creative mathematician without any knowledge of physics.

The subjects that were usually combined with mathematics were physics (in the conventional way) or economics or philosophy. Despite their educational value some students of mathematics found it irksome to have to master subjects that were alien to their interests and talent. In my own experience when working for the State Diploma in Berlin I had to offer physics as a second major subject, as well as chemistry and philosophy as minor subjects. It did not imbue me with liking for these fields of learning. I sometimes put forward the argument, which was not accepted by my colleagues, that mathematicians should be exempt from learning a second subject because the very word "mathematics" is a plural noun.

By far the most important novelty for me was the teaching in tutorials. Not having had the benefit of an education at Oxford or Cambridge I had no previous experience of this highly effective and satisfying form of instruction. At Sussex we were not able to offer the one-to-one relationships available at the ancient universities. But our tutorial groups of up to five students were small enough to get to know each student personally. I greatly enjoyed this form of teaching and I hope my students did too. It is a great pity that on account of financial stringency tutorial teaching had to be abandoned at Sussex and was replaced by the less personal use of exercise classes comprising some twenty students. The mathematics lectures at Sussex were much the same as everywhere else. But students were encouraged to write essays at various stages of their course, even as part of their Final Degree. Apart from the course tutors each student had a Personal Tutor with whom he could talk about personal matters. Rushi and I were always pleased to invite our personal students to our home.

Since many of the founding fathers had come from Oxford, some attempts were made to turn Sussex into a "Balliol-by-the-sea" and transplant into it some peculiar Oxford customs. We started by having to wear gowns when lecturing. At the very beginning some academic meetings were scheduled to take place on a Saturday morning. But Bernard objected to these on the grounds that on a Saturday members of faculty should be free to play golf or else attend Synagogue. The Oxford ceremony of "leave taking" was initially carried out at Sussex: at the end of term each student, wearing a gown, had to appear individually at the tutor's office. He summarized the student's performance during the past term often adding a stern admonition saying he or she should have done better. Some tutors seem to think that they were failing in their duty, unless all the girl students had left their office in tears. Mercifully, the few non-Oxbridge members of the faculty succeeded in persuading their colleague that these archaic practices are not appropriate in a modern university and they were abandoned in due course.

But some personal problems remained. The Government had refused to provide funds for the building of Halls of Residence for the students on the grounds that there are plenty of small guest houses near the sea front in Brighton which are used only in the summer months when the university would not be in session. So the students should live in guest houses. The proprietors would have to accept certain conditions. Of course, there would be strict segregation of the sexes. A desk with suitable lighting would have to be provided for study. The owners of the guest houses appointed a committee whose members would negotiate with the University and in particular with the Senior Tutor Patrick Corbett, the worldly Professor of Philosophy. But this apparently sensible solution of the accommodation problem soon ran into difficulties. After housing the students for one year, the representatives of the guest proprietors requested an interview with the Senior Tutor. The spokeswoman opened the meeting firmly with the words: "we do not want students in out guest houses any longer." Obviously this was an extremely serious threat. In the absence of alternative accommodation the University might have to close down at least for some time. So Patrick tactfully enquired about the reason for their discontent. As no answer was forthcoming he suggested: "Perhaps some students are a little untidy; or they are noisy, playing their radio; or (broaching a delicate subject) you object to the visitors they receive, especially late in the evening: tell me frankly what the trouble is. I promise you that it will be treated with strict confidentially." Finally, the spokeswoman responded: "It is none of things you have mentioned;" and she went on with indignation: "Do you know what the students do? They bring books into their bedrooms. We have been in the catering business for twenty years and more. Our guests are usually nice couples from London. They have their high-tea; then they go to the cinema and when they come back, they have a night cup and go to bed. But they never bring books into their rooms." Patrick assured them that there was nothing wicked about this habit; that some students want go on with their work late in the evening; and the University will offer them two shillings more per week to cover the cost of the additional electricity. The ladies of the committee took their leave and all seemed to be well - but only for a short time. At the end of the next academic year they came back and declared firmly: "We do not want to have students any more." Patrick enquired what the trouble was this time. "Do you know what they do? They have parties in their rooms. As there are not enough chairs, sometimes three big chaps would sit on the mattress, which is ruined by their weight and we cannot offer the bed to our summer visitors." This was obviously a "weighty" problem. When the matter was discussed at the Senate, the Vice-Chancellor asked the Professor of Mechanical Engineering to give his opinion as to how many "big chaps" could sit on a mattress without causing irretrievable damage. However, by now the University had come to the conclusion that was unwise to remain hostage to the landladies and it was decided to build accommodation on the spacious and beautiful campus. Unfortunately, since the project had to be financed privately, the rent for the students was rather high.

When the University was founded, the age of majority was still 21 so that most of our students, at least during the first two years, were "minors" and legally debarred from making certain decisions. I remember the case of a student who contracted acute appendicitis and needed an urgent operation, but his parents were in South Africa and could not easily be contacted. So the Senior Tutor had to give consent to the operation in place of the parents. On one occasion Rushi and I had to go to Registry Office to act as witnesses for the wedding ceremony of two of our students.

Another aspect of the paternalistic regime was the rule that students were not allowed to be absent overnight from their lodgings unless they had obtained prior permission (an exeat) from the Senior Tutor.

Fortunately, all these troublesome restrictions were abandoned once all students had become adults in law.
My colleagues at Sussex.

When mathematics was first taught at Sussex in 1962, the mathematics faculty consisted of five members: Bernard Scott as the Professor, myself as a Reader, and three lecturers: Ruth Rogers, Kathleen Trustrum and Brian Trustrum. It was a little odd that all three Lecturers were specialists in Hydrodynamics, a subject initially not in our syllabus. But we were all willing to adapt ourselves to the task of building up a sensible course of mathematics which would fit into the idea of this new and enterprising university. I think that, on the whole, we succeeded. A great deal of credit should be given to Bernard for his guidance and determination. His style of leading the mathematics "subject group" was, on the face of it, democratic: there was a faculty meeting every Monday morning at which coffee and biscuits were served. We discussed faculty business, for example lecture schedules, in a relaxed and friendly manner. But when it came to make crucial decisions, Bernard expected that his opinion should prevail.

The mathematical faculty grew very rapidly. Of course, most of my colleagues were much younger than I was. Indeed, apart from the Vice-Chancellor I was the oldest member of the University. It is therefore not surprising that I was asked to sit on a large number of committees which dealt with administrative matters and with the welfare of the students. I recall one particular week in which I spent 25 hours in committee meetings. I thought this was unfair since a Reader should use his time principally for teaching and research. It would be different if I had been a Professor who is expected to devote a reasonable time to administration. I made this point to Roger Blin-Stoyle, who was Professor of Physics and Dean of our School. He was sympathetic to my argument, and on 1st April 1965 I was appointed to be a Professor of Mathematics. I was told later that the Astronomer Royal objected to my appointment because "I was too old." But Bernard supported me strongly and the objection was overruled.

Soon more Professors were appointed, who specialized in Analysis, Applied Mathematics and Statistics respectively. Our mathematics group was well respected. As a result of Bernard's reputation we received distinguished visitors from abroad, who offered interesting courses of lectures. After a few years it decided that the Chairmanship should be held in rotation. The person, who was elected by his colleagues and who need not have professorial rank, should hold the position for three years. When my turn came in 1972-5, there were forty-two mathematicians at Sussex, including six professors. We all got on well with one another. Our excellent Secretaries contributed a great deal to the smooth running of the school, both for the members of faculty and for the students. Our sincere thanks are due especially to Christine Glasson and to Sue Bullock for their unfailing help.

It was tragedy for British mathematics and a disgrace for the University of Sussex that the School of Mathematical Sciences was closed down in 2003. A group of sixteen members, four of whom had already retired, was moved to the School of Engineering and continue to teach what mathematics is still deemed necessary. The scale of destruction can be measured by the fact that at the University of St Andrews the mathematics faculty has fifty-three members including twelve Professors.
Teaching activities.

My teaching commitments occupied more of my time that it did at Manchester and St Andrews. In addition to the formal lectures I saw several of the small tutorial groups each week and I talked to my personal students when the occasion arose. The students who wrote essays required preliminary instruction followed by supervision and assessment.

Throughout the University great importance was attached to high standards in teaching. Being one of the senior members of the faculty I was put in charge of a committee to look into ways of improving the teaching. With their permission I attended lectures given by my colleagues and made some suggestions. But in my report I recorded the melancholy conclusions that "good lecturers are born and not bred."

The mathematics faculty also provided help outside the University. Bernard was instrumental in founding the Sussex Branch of the Mathematical Association, which catered for school teachers in the area. It became a flourishing Society. We often attended its meeting and sometimes gave a talk. As elsewhere in the country there was a dearth of capable mathematics teachers in our area. So Bernard arranged refresher courses for teachers. These were well attended by teachers from schools all over Sussex. I was one of their lecturers on several occasions.

At the other end of the age scale of there were master classes for pupils aged about fourteen years. These were held at the University on Saturday mornings. I was very pleased to contribute a course on amusing arithmetic. After a short introduction I set some problems. The students were then distributed into small groups and supervised by a teacher who helped them to solve the problems. I think the scheme was quite successful.

Another teaching commitment was associated with the Arts/Science Scheme. It was considered desirable that all arts students should attend some lectures on science or mathematics, and that, conversely, all science students should have some acquaintance with arts subjects. I attempted to give some lectures on mathematics that, I thought, would be of interest to arts students. I think my efforts were only moderately successful. In any event, the scheme was soon abandoned. For the arts tutors were unwilling to expose their students to any contact with science or, even worse, to mathematics.

A more rewarding and worthwhile form of teaching was part of the European Course: capable students at Sussex were encouraged to follow a four-year course for the B.Sc. degree. This involved spending their third year at a university in a European country where they continued the studies of their major subject; at the end of that year they were required to write a dissertation in the foreign language which counted towards their degree assessment at Sussex. After their return from abroad the students continued their course at Sussex leading to a B.Sc. degree. The local authorities had agreed to provide financial support for this extra year. Most of the students who had volunteered for the European course chose to go to France; but a small number wanted to go to Germany and an even smaller number to Italy. It was a condition that they had an A-level qualification in the language of the country of their choice. But we realized that although they may have a good knowledge of the written and spoken foreign language, they would not be familiar with technical mathematical terms in French, German or Italian. So it was decided that prior to their departure the students on the European course should have one tutorial a week in the foreign language. It was fortunate that the faculty could provide this service; one of my colleagues had spent some time in the French speaking part of Canada and another colleague had done research in Rome. I was willing to give tutorials in German, which I quite enjoyed doing although it was more than forty years since I was a student in Germany.
External examining.

Because my first degree, or its equivalent, was taken at a German university in the 1930's I was never presented with an unseen paper from which I had to answer a specified number of questions in two or three hours. It is therefore somewhat ironical that after I had reached a certain seniority at a British university, I was asked to act as external examiner by a rather large number of universities in the British Isles. They included Edinburgh, Glasgow, Keele, Canterbury, Southampton, Birmingham, Wales, the Open University and the National University of Ireland. Each appointment was for three or four years; in some cases two visits were required in a year. So the number of journeys I made as an external examiner must have added up to about forty.

The duties of an external examiner involve scrutinizing and commenting on the draft of the questions before the examination and deciding with the resident colleagues what grades are to be awarded to the candidates after the examination. The work was not particularly arduous. After all, routine questions did not differ greatly from one year to the next and from one university to another.

Without exception, my visits as external examiner were pleasant experiences. Quite often I was offered hospitality by one of the resident colleagues, even with chamber music when I was staying with Hans Liebeck in Keele. The examiners' meetings at which the assessments of the candidates were decided were always conducted in a friendly manner; I never encountered any controversies or disputes. My appointment to the University of Wales involved visits to Cardiff and Swansea. Each place had its own examination papers, which I had to approve. My examiner's duties for Ireland were even more numerous. For the National University of Ireland consisted of colleges in Cork, Dublin and Galway each setting different examination questions which I had to scrutinize. Moreover, only one examiner in mathematics was appointed. His services were required for assessment of a course of Elementary Mathematics, an Honours Course in Mathematics, a Doctorate in Mathematics and some mathematical work at a Theological College. Examinations were held in June and in September, and the external examiner was expected to be present on both occasions. So during my tenure of this office I was kept rather busy. Early in the year numerous registered parcels arrived with the draft of the questions. My secretary was quite sorry for me. "Yet another parcel has arrived from Ireland," she said. But I consoled her: "Don't worry, Ann. In the last century Gladstone was troubled by the Irish Question. But I am not bothered by a hundred Irish Questions." I started my tour of duties at Cork. After that I spent some very pleasant days in Dublin and finally travelled by taxi to Galway. Everywhere I was received with warm hospitality. After my last visit as External Examiner Rushi joined me and we had a delightful holiday in the beautiful Irish countryside.

My association with the Open University extended over eight years, during which I acted as External Examiner for the course known as 'M335'. At the end of this period I was presented with an attractive cup on which was engraved: "Walter. THE OPEN UNIVERSITY FOR 8 HAPPY YEARS OF M335." I also examined for other courses and acted as an advisor and assessor for the construction of new courses. To my surprise and delight the Open University conferred on me the degree of Honorary Doctor in 1993. The Degree Ceremony was held in Edinburgh, where 53 years earlier I had received the Doctor of Science degree. But on that occasion on account of the war no ceremony was held and the Certificate was handed to me in a corner of the University Library.
Foreign travel.

It was a pleasure to be invited by a foreign university to take part in a conference or to give a lecture, sometimes even to give a course of lectures.

My most extensive visits were to the United States of America. When I was still at Manchester Saunders MacLane invited me to come to Chicago for a few weeks to talk about my recent work with Peter Hilton. It was my first experience of America; on the whole my visit to Chicago was very pleasant. I enjoyed the beautiful shores of Lake Michigan and the superb Art Collection (Art Institute). All the people I met were friendly and hospitable. But there were also some less agreeable moments. I first went to New York to visit my uncle Ernst (my mother's younger brother). I had my violin with me because I hoped to have some music in Chicago. When I got off the aeroplane I was seized by two excited customs officials who got hold of my violin case shouting: "What is in there?" I was surprised and answered innocently: "A violin;" I was ignorant of the fact that gangsters often carry their gun in a violin case. I arrived in Chicago on a Sunday. The weather was hot and I decided to go for a swim in one of the public beaches along the shores of the lake. When I came out of the changing room, I noticed that an armed police man was on guard and that I was the only white person on the beach. On the next day I told MacLane where I had been and he said: "You should not go there. It is a black beach."

Several more visits to the United States were to follow. After the Russian triumph with their priority of their Sputnik the American government decided to increase the number of people with expertise in mathematics and generally make the subject more popular. The National Science Foundation (NSF), which was funded by the government, instructed several universities in the States to hold Refresher Courses in the summer vacation. These courses were, in the first instances, intended for school teachers of mathematics, who were given the opportunity to consolidate and increase their knowledge of mathematics. One of the places selected for such a Refresher Course was the University of Notre Dame in Indiana. I do not know how it came about that I was recommended to be one of the teachers for their summer course. I was pleased to accept the invitation in 1962 and the subsequent two years. Unfortunately, Rushi and Jonathan could not come with me. The University of Notre Dame is situated in a large beautiful campus, not far from South Bend, a small provincial town. It can be reached fairly easily from Chicago. The university is a Roman Catholic institution. Most faculty members were Roman Catholic and many were priests (Fathers), except the Chairman of Mathematics, Arnold Ross, who was of Russian-Jewish origin. He was devoted to teaching and generally to widen the interest in mathematics. It was his ingenious idea to invite to the Refresher Course a selected group of gifted high school boys aged about 15. I gave my lecture early in the morning because it got very hot later in the day. After my lecture I went to the excellent indoor swimming pool, reserved for men in the morning and for women in the afternoon. There were rather exaggerated rules for hygiene: bathers were not allowed to use their own swimming trunks and towels. They had to take a shower watched by an attendant, who then gave them white swimming trunks and a bath towel. When I collected my linen parcel from him, he said deferentially: "Here you are, Father." I offered to give a simple course on group theory. Many members of my class wanted to buy a copy of my text-book Introduction to the Theory of Groups, published by Oliver & Boyd in Edinburgh. The manager of the University Book Shop thought it would be simplest to order a consignment of fifty copies direct from the publishers in Edinburgh. This was promptly done and a rather large package arrived at the Airport in Chicago. But now an unforeseen difficulty arose. It was the height of the Cold War and of the anti-communist witch hunt in America. The custom official inspected the consignment of my book. Evidently, he did not understand the contents. But the title was suspicious: Theory of Groups - what groups? he asked himself. Probably, what this foreign author has in mind are Groups of Communists or Anarchists. So the whole consignment was confiscated; it was released only after intervention by the President of the University, and the books reached my students albeit belatedly.

The University of Notre Dame was visited by eminent mathematicians from different countries and they were always received with warm hospitality. I met many interesting people there. On one occasion, the guest was a famous Polish mathematician. He spoke little English. As usual a dinner was given in his honour. Before the meal started, the Chairman went to the place where the guest was sitting and asked politely: "Professor, would you like to have Rosé tonight?" With a gleam in his eye the visitor chuckled: "Why not if she is pretty!"

The University of Notre Dame was famous for its prowess in the game of football. I felt very much honoured when after one of my visits I was presented with a sweater bearing the insignia of the celebrated team. Needless to say, I never had occasion to use this garment.

At the end of my second year at Notre Dame I was offered a permanent position as Professor of Mathematics. (I was still only a Reader at Sussex.) I felt pleased by the trust my colleagues at Notre Dame had in me. But I declined the tempting invitation because I felt that my family and I would not be happy settling down in a provincial town in America. Although everyone at Notre Dame was very kind to me, it was nevertheless strange surroundings for me. In any case I am too much a European. At about the same time I was offered a Chair in Australia which I declined for the same reason.

In 1963 Arnold Ross left Notre Dame and accepted the Chairmanship of Mathematics at Columbus, Ohio. He was going to continue the summer program there and invited me to join him the following year, which I was very pleased to do. As always I received a generous fee for my work and on this occasion it was possible for Rushi and Jonathan to join me in America after I had finished my lectures. I met them in New York, and we travelled across the States to California with a visit to Disney Land as a special treat for Jonathan. I regret that this was my last teaching engagement in America.

One of the people I met at Chicago was the Danish mathematician Svend Bungaard from the University of √Örhus, a pleasant town on the East coast of Jutland with an outlet to the Baltic Sea. Rushi and Jonathan accompanied me on this occasion. After I had completed my course of lectures we made an enjoyable trip to Copenhagen before returning to Sussex.

Several foreign journeys were due to invitations sent to me by some countries at the request of former students. I was a guest speaker at a meeting of the Iranian Mathematical Society. It was agreed that instead of paying a fee, the Society would arrange for me a tour of the country, which enabled me to see some of the beautiful historical places of ancient Persia.

On another occasion a student from Bangladesh, who had enjoyed his stay at Sussex, made arrangements for my colleague Gavin Wraith and me to be invited to address a meeting of the Bangladesh Mathematical Society, which was held in Dacca, the capital of the country. We had a friendly reception. But the poverty and drabness of the place was rather depressing.

An interesting but only moderately enjoyable experience was my participation at the International Congress of Mathematicians in Moscow in 1966. The lecture rooms were overcrowded and uncomfortable and I did not attend many lectures. But I saw a very good performance of a ballet. Since the University of Sussex had nominated me as their official delegate, I was privileged to have a personal guide; he was a young Russian student who spoke excellent English. However, there were limitations of what he was allowed to show me. When visiting the Art Gallery, which I believe, houses a large collection of beautiful classical paintings, I was permitted only to see the contemporary "socialist" pictures. One day I saw a long queue stretching through a street in the centre of the town. I asked my guide what these people are queuing for and he said: "They want to see the body of Lenin which is displayed in the mausoleum." I was not particularly keen to see this exhibit. But my guide thought that it would be appropriate to show it to me. He took me to the head of the queue and exchanged a few words with the armed soldiers guarding it. Immediately, a passage was made for us ahead of the waiting crowd. When we entered the mausoleum my guide said: "You must not speak now, like in a church." We entered the room where the dead body of Lenin lay in a glass coffin. He was dressed in a suit in the fashion of the 1920's.

At the end of the Congress I had a few roubles left and I wanted to buy a bottle of genuine Russian Vodka to take home with me. But the shop in the hotel refused to accept the national currency. I was told that anything I take out of the country has to be paid for in "dollars."

In 1974 I made a memorable visit to Mexico. A few years earlier Araceli Reyes de Gonzales had come to Sussex with her husband Cesar, a physicist, who was engaged in a research project over here. She had a first degree in Mathematics from the university in her country. I suggested to her that she might continue her studies of mathematics at Sussex University and preferably work for a doctorate. I chose a topic that I thought would suit her and I supervised her research. In due course she obtained the D.Phil. degree from Sussex. She and Cesar had become friends of our family. After returning to Mexico she was appointed to a senior position there. It was at her initiative that I was invited to give a course of lectures at the University of Mexico (in English since I do not speak Spanish). After my course, for which I received a generous fee, Rushi joined me and we had a most interesting trip which took us to many places in this fascinating country. A little later Jonathan and Sarah also made a journey to Mexico.

The most rewarding trip abroad was my visit to Israel in 1972. I had just been made Chairman of the Mathematics Faculty at Sussex and I had asked my colleagues to give me sabbatical leave for one term before I had to discharge the administrative duties which my new position would entail. I stayed with my sister Ruth in Tivon. My mother lived in an old-people's home nearby. I had been invited to give some lectures at the Israel Institute of technology (The Technion) in Haifa. It was quite easy to travel from Tivon to Haifa, as there was a fairly frequent direct bus service. The subject of my course was Group Representations; it was based on a course given by Issai Schur in Berlin in 1931. Since I do not speak Hebrew, I lectured in English. The secretary of the Technion was very helpful. She rapidly produced a typewritten version of my lecture notes, which was bound into a book and was offered to the students for a small fee. In some way, a copy of this book found its way to the editors of the Cambridge University Press. They wrote to me and asked whether I should be willing to have my Haifa Notes published as a book by the Press. Of course, I was pleased to agree. However, I pointed out that the Haifa Technion had the copyright and a publication could only be undertaken with permission from the Technion. This was graciously granted. But I stipulated that any royalties from the sale of my book should be shared in equal parts by the Technion and myself. I do not know whether in the four hundred years of its existence the Cambridge University Press had ever entered into such arrangement before. The book was published in 1977, followed by a second enlarged edition ten years later.
Retirement (official and otherwise)

The statutory age of retirement for university posts is 65 which I reached in 1976. My successor was duly appointed. But he was in the midst of a Royal Society research contract and was debarred from undergraduate teaching for the next two years. So (Lord) Asa Briggs, who was Vice Chancellor at that time, asked me to come to his office and said: "Walter, you have hardly changed since I first met you about fifteen years ago. I suggest you carry on in your position for another two years until your successor can take up his duties." Of course, I was very pleased to accept this invitation. However, as I discovered later, some of my colleagues, mainly physicists, resented the Vice-Chancellor's decision, which, they said, was high-handed and should been brought before the faculty for discussion. I am pleased to say that I was not aware of hostility amongst my mathematical colleagues. In 1978 my official retirement was inevitable. I was touched by the immense generosity and good will with which this event was celebrated. I knew that most of the ideas behind it were due to Bernard Scott and I am deeply grateful to him for the friendship shown to me, especially since in our professional endeavours we did not always fight on the same side of the barricades, On 17th June 1978 a Supper Party was held in my honour in the University Refectory, 7.00-11.00 p.m. Guests were received by Sir Denys Wilkinson, who was the Vice-Chancellor at that time. It was a truly magnificent occasion. Bernard had written to all my former students and to many of my friends who were not at Sussex. A booklet was published: Walter Ledermann. University of Sussex 1962 - 1978" in which 309 names were published of those who had replied to the invitation whether or not they were able to come to the Party. From the collection of money (not more than 50p each) I was given a beautiful Swiss watch, which I am still wearing. One of the students wrote to say that since I often make mistakes when carrying out numerical work on the black board, it would be appropriate that I should be given a pocket calculator. This was done, and I still have it. During the Party chamber music was performed by a group of colleagues and former students, and flowers were presented to Rushi. Arthur Craven, who was Chairman of Mathematics at that time, made a very friendly speech. He said: "Although this is a retirement Party for Walter, I do not believe that he will actually retire from being active as a mathematician." He was right: I remained in Sussex for another 18 years giving occasional lecture courses and keeping in touch with colleagues and students.
Association with John Wiley.

The Library of Mathematics ("penny shockers") which I started in Manchester continued to grow after I moved to Sussex. New volumes were written by some of my colleagues at Sussex but also by mathematicians whom I met during my visits as external examiner or who were recommended to me. I edited all these contribution and I was pleased that the series eventually comprised more than twenty titles. It is a great shame that when my publishers Routledge & Kegan Paul were taken over by a large American firm, the whole series was taken out of print, because there was not enough profit in selling "cheap & nasty" little books, however much they were appreciated by the public. I had invested a great deal of thought and time into producing these text-books for the benefit of our students, and I was disappointed that my efforts were annihilated by commercial greed.

However, my wish to communicate mathematics to a wide audience found another outlet. On one of his routine visits to the University of Sussex a representative of he publishers John Wiley & Sons asked me if I would like to write a text-book to be published by Wiley. I told him that in my opinion Wiley's books were too expensive for most students. Instead, I suggested that I might act as editor of a comprehensive work of reference for people who are not mathematicians but use mathematics in their profession including physicists, engineers, statisticians, psychologists, economists and many others. My idea was to provide a simple exposition of "useful" or "applicable" (not "applied') mathematics. The idea appealed to the director of Wiley and I received a contract to go ahead with the project which I called a Handbook of Applicable Mathematics.

The intention was to present the mathematical material in CORE VOLUMES, one for each branch of mathematics, such as Algebra, Analysis, Geometry, Probability. The Core Volumes were to be supplemented by GUIDE BOOKS each referring to a profession in which mathematics is used and where references would be given to the appropriate section of the core volumes, such as Mathematical Methods in Economics. It was a formidable task. But I was extremely fortunate that I was supported by a very able and friendly Editorial Board. It included Robert Churchhouse, whom I knew from his student days at Manchester. He took charge of the volume on Numerical Methods. Emlyn Lloyd, of the University of Lancaster, edited the core volumes on Probability and Statistics. The other core volumes were edited jointly by Steven Vajda (Sussex University) and myself. Peter Hilton represented the Handbook in the United States and I was pleased that he was able to attend some of the meetings of the Editorial Board during his visits to England. My work was greatly helped by Carol Alexander (Carol van der Plough) as the devoted and highly efficient Assistant Editor. The meetings of the Board were organized and chaired by Jamie Cameron who was appointed by John Wiley to be our editor. The meetings, at Wiley's expense, took place at a West End Club, of which Jamie was a member. The Club had rather strict rules in regard to admission of visitors. On one occasion, when Peter Hilton turned up in an open neck shirt, he was refused entry and we had to go to a gentlemen's outfitter where Jamie bought a proper shirt and tie for Peter (again at Wiley's expense). It happened to be quite an appropriate occasion, because it was Peter's birthday. The meetings were always conducted in a very amicable manner and I always felt that I was among friends. The first core volume appeared in 1980; the series was concluded with the Index Volume, which was published in 1991. There were also several years of planning before publication began. So the Editorial Board was active for about fifteen years. We produced six Core Volumes and a Supplement comprising together about 5000 pages. The articles in the Core Volumes were written by 60 authors, not all of them from the United Kingdom.

Numerous review articles about the Handbook of Applicable Mathematics ("Ham" for short) appeared in journals throughout the world. The assessment was usually quite favourable. Also I gathered that Wiley was satisfied with the commercial aspect of the project. Indeed, when I spoke to the Manager of Wiley he remarked: "The Handbook of Applicable Mathematics is our flagship." I visited Wiley's office at Chichester several times and I was always received with warm hospitality. The racecourse Glorious Goodwood is situated near Chichester and Wiley owns a beautiful room overlooking the race course. On one occasion Rushi and I were invited to join them there to watch one of the races (a unique experience for us). We were welcomed by the Duke of Richmond who owns the course. Rushi took a bet on a horse and won one pound.

Wiley's principal office is in New York. At one stage of my work on our project I was sent there (at their expense) to discuss matters of common interest with the management in America. During my visit I stayed at the luxurious Wiley apartment in Manhattan. On another occasion Wiley sent me as their delegate to a conference on publication which was held at an attractive former castle in East Germany, which was interesting for me apart from the topic of discussion.

In addition to my work as editor of "Ham" I was engaged by Wiley as one of their advisors on mathematics. For a modest annual salary I was asked to give my opinion on proposals for the publication or translation of mathematical texts. One of these was by the French mathematician Françoise Chatelin on "eigenvalues". I thought her book would be of considerable interest to English readers and since the topic was in my field of interest, I offered to do the translation myself. It was the only time that I have done this kind of work. Evidently, it was quite well received because my English version went through two editions.

I was sad when my contact with Wiley ceased after more than twenty years. It had been a most valuable experience. I was grateful for the friendship I formed with the members of the editorial board and the contributors of the mathematical articles, and I enjoyed the contact with the appreciative and supportive staff at the Chichester Office.
Research at Sussex.

Considering the effort which faculty members expended on teaching and on caring for our students both on an academic and on a personal level, it is perhaps not surprising that mathematical research moved into a secondary place. This was partly due to a lack of leadership. When I was appointed to a Chair, I now believe that some of my younger colleagues expected me to arrange weekly meetings of a Research Seminar, at which recent papers or books would be discussed and further research would be stimulated. For whatever reason I did not do so, and I regard this failure as the greatest defect in my career. The mathematics subject group produced less original work than members in other subjects, notably the chemists who soon counted several Fellows of the Royal Society in their group; no mathematician was elected to the Royal Society while at Sussex. Regrettably, several newly appointed faculty members left Sussex after a year or two because they wanted to be at a university where more encouragement was given to research.

In my case further demands on my time and energy were made by the publication of text books and later by editing the Handbook. After all, I was more than fifty years old when I was appointed the Chair, and my strength though not my enthusiasm, was no longer at its highest level.

Nevertheless, I trust that I have done my fair share in supervising research students, all of whom were successful in obtaining the D.Phil. degree. This was the kind of work which gave me great satisfaction. Also I had the pleasure in being the joint author of some research papers. I published two papers with Carol: one on a topic in pure mathematics which arose out of her doctoral dissertation and, after she had taken a degree in Economics at the London School of Economics and returned to Sussex as a member of the faculty, we cooperated on some investigation into an economic problem. Steven Vajda and I published a paper on a statistical question of interest to him. When the paper appeared in print, Steven was ninety years old and I had passed my eightieth birthday. Perhaps it is not surprising that henceforth our productivity was declining ... .