Denys Armstrong, who died on 29 November 2006, was on the teaching staff of this Department, as University Demonstrator 1952 - 4 and as University Lecturer 1954 - 1985. In his early years he made important contributions to research: e.g. he supervised W.L. Wilkinson, F.R.S, who worked on the unsteady state behaviour of distillation columns. But Denys's major contribution was in teaching and administration. He arranged the lecture schedules, taught many of the courses, and established links with several Colleges at which he was Director of Studies. He managed the Departmental accounts and, with Professor Terence Fox, designed the new "Shell" building which opened in 1959. Denys did much work on committees of the Institution of Chemical Engineers and on committees of the Engineering Council, e.g. in establishing the M.Eng. degree, now our primary qualification. Several of us remember his work over very many years for The Engineering Council's own examinations; all that continued long after he retired. He was a founding Fellow of Churchill College, where he was closely involved with the detailed design of all the College buildings. For many years he was Secretary of the College Stewards' Committee and introduced the bulk buying of food by groups of Colleges. He was the University's expert on V.A.T., very much to the benefit of those of us who ran conferences. Another of Denys's interests was wine - he was Wine Steward at Churchill and later St John's - where his knowledge was encyclopaedic. Given his expertise, he drank surprisingly little. Always active after retirement, he put some of his energies into running private railway lines.
Perhaps Denys's most important, and least recognised, work was with students. He took a personal interest in everyone, particularly those in difficulties and steered people into appropriate jobs. Nowadays it is called counselling; Denys was a highly effective counsellor, respected by all students who passed through the Department. He knew them all on first-name terms.
From 1956-9, Denys Armstrong was my supervisor and my topic was to extend the work, started with Bill Wilkinson on the transient responses of distillation columns. This previous work had gone very well and Denys and Bill had been awarded the Moulton Medal by the Institution of Chemical Engineers, as one of their papers was considered to be the best published by the IChemE in the year 1957. Much to my surprise, I was able to come up with some simplifications for developing theoretical predictions and so my project worked out quite well. The expressions I derived were still not very 'user friendly' and today this work could be done routinely on digital computers. However in Cambridge at that time there was only one digital computer: EDSAC I (~1951-1958) and EDSAC II (1958-1965)!
English had not been a great subject for me previously and I found Denys enormously helpful in correcting and improving my draft thesis. This (long before word processors and photocopiers) was eventually typed with two carbon copies. Thus it was essential that the draft be virtually perfect, as making corrections to the typing, and separately to the copies, was very laborious. Prof Roger Sargent of Imperial College was my external examiner and I remember him complimenting us on the quality of the presentation, which was very much to Denys' credit.
I found Denys to be friendly and helpful, though usually his conversation was very much to the point, as he was so busy. In 1959 the Department left the temporary buildings in Tennis Court Road and moved into the luxury of the new building on Pembroke Street. Prior to this, Denys had been very much involved with meetings with the architects and others involved in the project. I think that his thoroughness in examining the details in this work, would have been a very positive factor in the success of this building. In the early 1960s, I believe that the design and construction of the new Churchill College (where he was one of the founding fellows) would also have taken up a lot of Denys' time and energy and this led, in 1967, to him being awarded an OBE.
Once my parents visited Cambridge and wished to meet my supervisor: this was probably towards the end of my first year, during which I had made little progress with my research topic! Thus we all had an excellent lunch at the Garden House outside by the Cam on a lovely sunny day. My Mother had been to College, but my Father had very basic education and left school at the age of thirteen. Nevertheless I was quite surprised at how good Denys was at helping them to be relaxed and keeping the conversation going, as I had never seen him in such a situation before. I think I even remarked about this afterwards to Margaret Sansom, Prof Fox's Secretary.
Compared to Prof Davidson and possibly some of the other staff, Denys perhaps may have been criticised for not doing more research. Thus, probably in 1961, I remember him saying that in that year he had five papers published, which was more than any other member of staff! (Nowadays, five papers would not be considered a large contribution, but the policy then was not to publish preliminary papers before a topic had achieved some definite outcomes and of course there were very few conferences to attend.) Situations where I also remember Denys' helpfulness are when he invited me to Churchill College and also in 1977 he helped facilitate my request to have a half year sabbatical back at Cambridge.
On completion of his thesis, Bill Wilkinson moved to Swansea and made a major contribution in founding the new Chemical Engineering Department there. He also had started work on the transient behaviour of distillation columns of an industrial size at the nearby BP oil refinery. However in 1959, he was moving to a post with the Atomic Energy Authority. Thus there was a ready made opening for me at Swansea and so thanks to Denys, I was able to start my academic career!
Robert M Wood
Formerly Associate Professor in the School of Chemical Engineering and Industrial Chemistry at the University of New South Wales