Sefton Hamann was born in Christchurch, New Zealand, on 8 January 1921 and died in Melbourne on 12 January 2009. He had a distinguished career in Australia’s CSIRO as a scientist, as Chief of the Divisions of Physical Chemistry (1960–1966) and Applied Chemistry (1966–1974) and as Chairman of the Applied Chemistry Laboratories Committee (1974–1978). He was internationally recognized for his lifelong contributions to the physico-chemical effects of pressure. He made a major contribution to the nation through his work on the polymer banknote.
Sefton Davidson Hamann was born in Christchurch, New Zealand, on 8 January 1921, the third child of Conrad Gustavus Hamann and Margaret Elizabeth Hamann (née Wilson), who had married in Dunedin in 1902. Conrad Hamann was a pianist, piano tuner and salesman. In 1908 the family lived in Sefton Street, Timaru, about 160 km south of Christchurch, but they had moved to Christchurch in 1917. By 1921, the family was living in the Christchurch suburb of Fendalton. Sefton’s mother was 42 years old, his father 48, his sister Margaret (‘Mollie’) 16 and his brother Conrad 14 when Sefton was born.
Sefton married Elizabeth Wayne Boden, daughter of Charles Wilfred Boden, an insurance officer, and Olive West at St Anne’s Parish Church, Strathfield, Sydney on 11 September 1950. They had met in 1944 at a dance in Sydney and were engaged to be married before Sefton went to England in 1947 to study for his PhD at the University of Manchester. It was a long engagement! Elizabeth Boden was deputy play editor and acting chief editor with the Australian Broadcasting Commission. They moved to Melbourne when Sefton became the Chief of the Division of Physical Chemistry in 1960. Elizabeth became a librarian and worked at the Presbyterian Ladies College in the Melbourne suburb of Burwood for many years. She and Sefton were married for 52 years until her death in 2003.
They had one child, Conrad Charles Hamann, born on 28 November 1951. Conrad married Christine Kathryn Corrigan in 1975. They have two children. Conrad is a distinguished art historian who ‘bridges what is usually the gap between the architectural profession and academic art history, by a very thorough, erudite and refreshed study of Australian architectural consciousness and its buildings’.
Sefton commenced his secondary education in Christchurch in 1934 at Christ’s College, Canterbury. This was a school established in 1851, modelled on the public schools of England; many of the original English settlers of the region sent their sons to it.
Sefton attended the school as a day-boy. The school records and family stories indicate that while he was not an outstanding student he did pass the Matriculation examination at the end of Form V in 1936. He was too young to enter university so went into FormVIin1937,but left after one term. He was not in any of the ‘first’ sporting teams although he did claim to his family that he was captain of the 7th eleven! Although he left the school without completing Form VI, he did seem to be proud to be an ‘old boy’ of the school. He wore the blazer while courting Elizabeth in Sydney (Fig. 1) and was an active participant in the Victorian Branch of the Christ’s College Old Boys’ Association.
After leaving school, Sefton began work as a clerk at the National Pensions Office in Wellington. Although this was clearly filling in time until he could enter university, his Certificate of Service in the Royal New Zealand Navy has an entry under the heading ‘Trade brought up to’ where it says ‘Clerk’.
In 1938, Sefton commenced a BSc course in Chemistry at Canterbury University College (then a constituent college of the University of New Zealand, now a separate institution, the University of Canterbury). His subsidiary subjects were Physics I and II, Pure Mathematics I, Applied Mathematics I and Psychology. In 1941, when he had qualified for his BSc degree and was part of the way through his MSc, he enlisted for war-time service in the Navy. With the war over, he returned to Canterbury University College in February 1946 and completed his MSc with First Class Honours in Chemistry. The title of his thesis was ‘The Solubility and Thermodynamic Properties of Lead Bromide and Lead Iodide in Various Methanol-Water Mixtures’, his supervisor being the then Associate Professor Hugh Parton.
In a reference for Sefton, the Head of the Department, Professor John Packer, wrote: ‘His written thesis showed an excellent grasp of the theory underlying his work, and a mark of 80 per cent was awarded by the external examiner, Dr R. A. Robinson.’ No refereed publications resulted from this work.
Sefton volunteered for naval service and was enlisted in Auckland on 23 October 1941. The Royal New Zealand Navy had been established only shortly before, on 1 October 1941; prior to that date, New Zealand naval forces were a division of Britain’s Royal Navy. Sefton was sent immediately to the Radar Branch and served there until his discharge on 24 February 1946.
New Zealand played its part in the development and deployment of radar during the Second World War. The New Zealand effort was directed by Dr (later Sir) Ernest Marsden and included Professor F. W. G. White (later Sir Frederick White, Chairman of Australia’s CSIRO) and C. N. Watson-Munro (later Chief Scientist of the Australian Atomic Energy Commission and Professor of Plasma Physics at the University of Sydney). The work took place in the Radio Development Laboratory (RDL) and has been well documented.
Sefton’s role in this work was as a Radio Mechanic. He rose to the rank of Petty Officer. He was under the command of Lieutenant Commander E. J. Marklew who wrote:
During this period he was under my command and displayed an outstanding knowledge of Radar technique. He was responsible for independent development and scientific investigation and contributed in no small manner to the success of Radar sets developed and produced in New Zealand as well as submitting constructive criticisms and improvements to Admiralty sets. He was seconded to the Radio Development Laboratory in Wellington where his standard of work was equal to that of the leaders of the sections of the laboratory. He served in the Solomon Islands and carried out important duties in the fitting of sets in cruisers and small ships at the Devonport Naval Base.
As part of Sefton’s secondment to the RDL, he spent six weeks at the Australian war-time radar research laboratory, the Radiophysics Laboratory in Sydney. In the Solomon Islands he had some encounters with the enemy, described in his own words:
I arrived in Guadalcanal from New Caledonia early in January 1944 in a party of about 10 members of the Royal New Zealand Navy, with the object of setting up a 240 MHz New Zealand designed radar station to provide sea warning and gun-laying support for a US Army artillery post at Cape Esperance, on the northern tip of the island (shore-based radar stations were then quite scarce in the South Pacific). At this stage, land fighting had ended on Guadalcanal but there were still incursions of Japanese aircraft and radar installations were among their natural targets. So we suffered recurrent alerts that slowed our work but did no other harm and the radar was working well within a few weeks.
After the land-based radar was set up, I was seconded to a small group of New Zealand corvettes patrolling the Coral Sea and the Solomon Sea, where the Japanese land forces still held out on some of the surrounding islands. In particular, I was on board HMNZS ‘Matai’ in, I think, late March 1944, when it joined some American warships to shell entrenched Japanese positions on the south-west coast of Bougainville. My recollection of the engagement is that the enemy returned our fire without success for a few hours and then appeared to have been silenced. In this action, my job was to help keep the ship’s radar working on a rather shaky platform.
After his discharge from the Royal New Zealand Navy in February 1946, Sefton completed his MSc at Canterbury University College and worked for a time at the Dominion Laboratory in Wellington, where he is listed as being employed as a Technical Officer Grade 1 for three months during 1947. During this time he revisited the Radiophysics Laboratory (by now the Radiophysics Division) in Sydney.
At this stage of his career, Sefton chose to develop his interest in solution chemistry by going to England to pursue a PhD in chemistry at the University of Manchester. Michael Polanyi had been the Professor of Physical Chemistry at Manchester from 1933 to 1947, when he moved to a chair in social sciences that was created for him. By the time he left, Polanyi had built a department in large part devoted to the study of the molecular basis of reactions. Sefton’s supervisor, Dr Alwyn G. Evans, was part of this group and was interested in the kinetics and mechanisms of organic reactions in solution; he continued work in this area until 1959. One of Sefton’s contemporaries was Michael Polanyi’s son, John C. Polanyi, who won the 1986 Nobel Prize for Chemistry (with D. R. Herschbach and Y. T. Lee) for his contributions concerning the dynamics of chemical elementary processes.
Sefton’s PhD thesis was a combination of theory and experiment, a characteristic of his whole scientific career. He developed a conductometric technique for measuring the rates of organic halide reactions and interpreted the results using transition state theory (1–6). The rest of his publications were from a CSIRO address except the last one, which was from his private address.
While in Sydney for short periods between 1944 and 1947, Sefton had become engaged to Elizabeth Boden and so was keen to return to Australia after completing his PhD. In July of 1948 he wrote to the Chief of the Council of Scientific and Industrial Research’s Division of Industrial Chemistry, in Melbourne, enquiring whether any positions would become available in the Division in about one year’s time.
The Chief at the time, Dr (later Sir) Ian Wark, replied saying that he was having more difficulty in finding physical chemists than organic chemists and for Sefton to keep in touch. Sefton wrote again in April of 1949 and Wark immediately dispatched Dr Keith Sutherland, who was then spending time at the Royal Institution in London, to talk to him. Sutherland was the officer-in-charge of the Division’s Physical Chemistry Section at that time. He thought highly of Sefton but did not think him the best fit for the possible vacancy in the Organic Chemistry Section. However, a position did become available in the Division’s High Pressure Laboratory, which was housed in the Chemical Engineering Department at the University of Sydney. Sefton applied for this and was appointed. He commenced duty on 5 January 1950.
The High Pressure Laboratory’s location in Sydney suited Sefton from a personal point of view. The scientific field was quite different, however, from his PhD area, so before returning to Sydney he spent the first few weeks of his appointment in England and Holland, where he was able to visit Professors E. A. Guggenheim, J. E. Lennard-Jones, D. M. Newitt and A. Michels. All were leading experts in the theoretical and experimental study of the properties of fluids, this being what Sefton was going to be working on, for the first time, in Sydney.
He rapidly made contributions to his new field. By 1952 he had published eight papers, five in the Journal of Chemical Physics, two in the Transactions of the Faraday Society and one in Nature (7–14). He had measured the second virial coefficients of some organic molecules, measured the dielectric properties of compressed fluoromethane and written a theoretical paper on intermolecular force models.
Before the development of molecular beams allowed the measurement of differential scattering cross-sections, most of our knowledge of intermolecular forces came from the analysis of gas properties. The virial equation of state was important because of its theoretical connection with the forces between molecules. Sefton developed a differential compressibility apparatus in which he compressed both the reference gas and the experimental gas so as to keep their volumes equal and then measured the resulting pressure difference between the two gases. He used this method to measure the second virial coefficient of a number of compounds including benzene, carbon tetrafluoride, silicon tetrafluoride and sulphur hexafluoride. He, with his colleague J. A. Lambert, devised a new model to describe the interaction between quasi-spherical molecules such as those of sulphur hexafluoride (21, 22).
The officer-in-charge of the High Pressure Laboratory at the time, Dr J. F. Pearse, resigned in February 1952 and, at the age of 31, Sefton was appointed to the position. This commenced a very productive decade during which he published 47 papers (9–55) and a major monograph. The papers published during this decade had 1,064 citations until 15th January 2009 and established his international reputation in the chemical effects of pressure. In this time he completed his work on virial coefficients and developed his work on the physicochemical effects of pressure. The latter combined his earlier interest in the molecular basis of chemical reactions and his new-found skills and interest in the study of phenomena at high pressures. In recognition of his growing international reputation, in 1955 he was granted six months’ leave to visit leading high-pressure laboratories in the USA, the UK and continental Europe.
Sefton’s monograph, Physico-Chemical Effects of Pressure, was published in 1957. The book has been cited consistently over the years and was last cited in 2008. The intention of the book was to bridge the gap between the physics of high pressure and the practical uses of pressure in the chemical industry. It provided a comprehensive survey and analysis of the effects of pressure on volume, phase changes, viscosity and diffusion, dielectric and optical properties and chemical kinetics. In the preface, Sefton provided an insight into his approach to science: ‘On the principle that it is better to have a rough guiding theory than none at all, I have tried to give molecular pictures of the underlying causes of the pressure effects, even though they are sometimes crude and underdeveloped. It is likely that time will prove some of the models wrong but in the meanwhile they will have a use if they merely stimulate further research.’
They certainly did for him! He measured the effects of pressure on electrical conductivities, on the rates of electrophilic reactions, on micelle formation, on the polymerization of maleic anhydride and on polyesterification reactions. He was not an inventor of new techniques; rather, he adopted and adapted techniques to suit the particular problem at hand. For example, in his paper with D. W. Coillet on the effects of pressure on the rates of electrophilic aromatic nitrations in solutions (55), the apparatus is similar to that described in the literature but modified because of the corrosive nature of the reaction mixture. This paper has a good example of some of the risks involved in this research: ‘We made only a few measurements in nitromethane because we found that this solvent forms extremely explosive mixtures with nitric acid. Pure nitromethane can be detonated by sudden compression to 150 atm, and we found that the addition of nitric acid makes it both a more sensitive and a more powerful explosive.’ They did complete enough experiments, however, to estimate the activation volume.
Sefton’s work was receiving international recognition, as indicated by his being invited to the 1956 and 1959 Gordon Research Conferences on High Pressure and to the 17th IUPAC Congress in Munich in 1959 (46), and to write chapters in major reviews (60, 61, 64).
Sefton published papers with 99 co-authors, mainly from Australia, the USA, France and Russia. He typically did not seek collaboration; others sought collaboration with him. His most frequent co-author was the CSIRO scientist Max Linton, with whom he published fifteen papers. This collaboration led to a series of papers, ‘The Influence of Pressure on the Infrared Spectra of Hydrogen Bonded Solids’ (105–108, 113, 119, 141), published between 1975 and 1988—the last several years after his retirement in 1983.
The series presented their measurements of the influence of pressures up to 40 kbar (4 GPa) on the hydrogen-bonded OH stretching and bending frequencies of solids whose hydrogen bonds covered the full range of strengths from very weak to very strong. The most usual change in the vibrational spectra of solids resulting from an increase in pressure is an increase in the frequencies of fundamental molecular bands. This ‘arises because compression increases the forces of repulsion between neighbouring molecules and between atoms and groups within individual molecules and so steepens the curvature of the potential wells that govern the vibrations’ (105). The series of papers analysed exceptions to this general pattern and used the experimental results to build models of interatomic potentials (Fig. 2).
Sefton’s international standing was further recognized in 1979 when the Swedish Academy of Sciences invited him to present a paper at the Nobel Symposium entitled ‘Chemistry and Geochemistry of Solutions at High Temperature and Pressure’ that they were organizing to mark the bicentennial of the birth of Jöns Jacob Berzelius. Twenty-five experts drawn from various fields discussed the chemistry of solutions at high temperatures and pressures; Sefton’s paper was on ‘Properties of Electrolyte Solutions at High Temperatures and Pressures’.
In October 1958, the Division of Industrial Chemistry of what was now called CSIRO was divided into independent Divisions and Sections under the umbrella of the Chemical Research Laboratories. Ian Wark was appointed Director of the CRL and Keith Sutherland the Chief of the Division of Physical Chemistry. However, Sutherland left CSIRO in November 1959 to become Director of Research at Commonwealth Sugar Refineries Limited. The position of Chief was advertised and re-advertised in 1959 and 1960 but none of the applicants was considered worthy of appointment. Wark was then authorized to invite Sefton to accept the position. Sefton did so on the understanding that he would be able to continue with some of his personal research interests. He took up the position on 10 October 1960. It was typical of Sefton not to seek a position of power.
When Dr J. R. Price, who was the Chief of the Division of Organic Chemistry, was appointed a member of the CSIRO Executive in 1966, it was decided to combine the Divisions of Organic and Physical Chemistry to form the Division of Applied Chemistry. Sefton accepted the invitation to be the Chief of the new Division. In 1973, he announced his intention to resign as Chief but he remained in that position until 1974 when the Division was divided, to form the Divisions of Applied Organic Chemistry and Chemical Technology. Sefton continued as chairman of the Applied Chemistry Research Committee until December 1978 when the reorganization of CSIRO into Institutes made the position redundant. He remained a Chief Research Scientist until his retirement in January 1984, aged 63, when he was offered a two-year Post-Retirement Research Fellowship in the Division of Applied Organic Chemistry. He continued as an Honorary Research Fellow in the Division and its successor Divisions (Chemicals and Polymers and Molecular Science) until ill-health prevented him from coming into the laboratory in 1999.
Sefton was a reluctant Chief. He did not apply for the position of Chief of the Division of Physical Chemistry in 1962 and was invited to become Chief of the Division of Applied Chemistry in 1966. These invitations were made on the basis of his scientific achievements and his broad interests in chemistry. In his letter to the CSIRO Chairman recommending the 1962 appointment, Ian Wark mentioned that in taking over the Division, Sefton ‘would not at first make any changes in organisation or research programme’. He was uncomfortable with the notion that CSIRO needed to generate external business. When asked what the newly appointed Assistant Business Manager was going to do, he answered: ‘I don’t know what the Business Manager does but whatever it is the Assistant is going to help him.’ He was also not particularly interested in developing formal plans or strategies. Indeed, when it appeared that CSIRO would need to justify its existence to Government and to explain its value to the community, he resigned from the position of Chief.
Sefton’s habit of coming to work on the first available public transport in the morning and leaving before 3 o’clock to spend time in a pub reduced his opportunities to interact with the rest of the Division, who tended to work the standard CSIRO hours of 9 am to 5.06 pm. He was very interested in the scientific standards of the Division and read and commented on all the papers leaving the Division for publication. He also took the responsibility of staff promotion very seriously. He wrote all cases for promotion himself, with the person concerned not knowing anything about the process until 30 June, when Sefton would send a letter informing him or her of the promotion. His interest in the science of the Division and in the fair treatment of his staff was appreciated and created a supportive atmosphere. This was especially appropriate in the immediate post-war decades when CSIRO was building up its and the nation’s scientific capacity.
A meeting was held on Monday 9 April 1968 at the Reserve Bank of Australia’s Melbourne office that would change the course of Sefton’s career as well as the careers of many other CSIRO scientists. The then Governor of the Bank, Dr H. C. (‘Nugget’) Coombs, called the meeting between his top note-printing staff and seven of Australia’s leading scientists to discuss techniques to produce notes that would be difficult to counterfeit. Decimal currency had been introduced in Australia on 14 February 1966 and shortly afterwards, substantial counterfeiting of $10 notes was detected (ironically as the convicted forger Francis Greenway was depicted on the note). A metallic security thread in the centre of the note was a security feature in the new notes but it soon deteriorated with the folding of the notes, reducing its value as a security feature. (It was moved away from the centre in 1974, making it less susceptible to deterioration and hence simulation by forgers.)
The scientists invited to the meeting were Sefton Hamann, Dr A. K. Head, Dr J. R. Price, Dr A. Walsh and Dr J. P. Wild (all from CSIRO), Professor K. G. McCracken (Professor of Physics at the University of Adelaide) and Professor J. C. Ward (Professor of Physics at Macquarie University). Of those present, only Sefton stayed with the project to its conclusion.
Many ideas were discussed at this first meeting, including the use of non-paperlike materials for currency notes and the use of diffraction gratings or Moire patterns to indicate inaccuracies in printing to register. It was agreed that someone with expertise in photography should be invited to the next meeting.
The next meeting of the group was held at the Thredbo Alpine Hotel over the weekend of 15–16 June 1968. The original members were joined by Dr N. B. Lewis, recently retired from the position of Director of the Kodak Research Laboratories in Melbourne (the person with photography expertise) and Dr D. H. Solomon (a CSIRO polymer scientist and co-author of this memoir, who had been consulted by Dr Price prior to the April meeting and recommended by Price to join the group). Solomon had suggested the use of ‘plastic paper’ as the substrate.
No formal project resulted from the Thredbo meeting, but the Reserve Bank’s Note Issue Department continued informal contacts with Hamann and Solomon. These contacts were to do with printing technologies and with special papers or ‘synthetic’ papers. The early research was done in the Divisions of Applied Chemistry, Mineralogy and Forest Products but was eventually confined to the Division of Applied Chemistry and then the Division of Applied Organic Chemistry. The early work was all funded from CSIRO’s own appropriation funds but in June 1971 J. P. Shelton from CSIRO’s head office wrote to the Bank: ‘Finally, may I mention that we are a little out of pocket in preparation of these samples and perhaps we should discuss at some time the possibility of a small grant from the Bank if further work along these lines seems to be desirable.’
The arrangements between the two organizations were eventually formalized in 1972 and the first meeting of the CSIRO–Reserve Bank Committee was held at Fishermen’s Bend in August 1972. The project was officially named the Currency Notes Research Development (CNRD) project in 1974 and the first meeting of the CNRD Committee was held in October 1974.
Sefton Hamann remained an important contributor to the project until his retirement in 1983 and during his period as a post-retirement Fellow and as an Honorary Fellow. His main interest was in the development of optically variable security devices.
From the notes of the first meeting in Melbourne, it is clear that diffraction gratings and Moire patterns were discussed in the context of their use in controlling printing rather than as security devices. However, between the Melbourne and Thredbo meetings some idea of their use as security devices appears to have emerged because in the notes prepared for the Thredbo meeting it is noted that ‘some simple experiments have been done to obtain photographic simulation of diffraction grating effects’. Sefton’s own recollection was that Dr Alan Walsh suggested the use at the Thredbo meeting.
The Bank’s interest in diffraction gratings was further catalysed by a letter from Dr E. G. Bowen (Chief of the CSIRO Division of Radiophysics) who had sent a diffracting film that he had bought from the Army and Navy Store in London in September 1971 and a sample note prepared by D. H. Solomon that included a metallized patch on a polyester film. Bowen had been involved with the Bank in the earliest discussions of possible scientific work on forgery-proof banknotes but was not involved in any of the subsequent meetings.
Sefton devoted much of the next decade to working on optical variable devices. He was personally interested in Moire interference patterns—patterns created when two grids are overlaid at an angle or when they have slightly different mesh sizes—and also helped supervise the work of Dr Bob Lee who was recruited by CSIRO to develop diffraction gratings suitable for incorporating into banknotes (Fig. 3). Sefton was the co-inventor with D. H. Solomon and M. F.W. Brown of the patent ‘Improvements in or relating to security tokens’ lodged in September 1973.
No account of Sefton’s career would be complete without some reference to the court case that arose from an Operational Health and Safety issue involving the use of a laser. The case was a source of great distress to Sefton. One of the experimental officers working with Sefton on setting up a newly purchased laser claimed that Sefton had allowed reflected light to injure his eye. Sefton vigorously denied the charge. It went to trial by jury but was quickly settled out of court.
Sefton seldom applied for or volunteered for positions or activities. He was usually enlisted by others. He joined the Royal Australian Chemical Institute (RACI) as a Fellow in 1964 and was awarded the RACI’s prestigious H. G. Smith Memorial Medal in 1969. The conditions for the award are that ‘The major proportion of the work shall have been done in Australia or its Territories while the candidate was a member of the RACI. The Candidate shall be and have been a financial member of the RACI for at least three years.’ It is difficult not to draw the conclusion that his nominator for the award approached him assuming that he was a member of the RACI, discovered otherwise, nominated him as a Fellow and waited the due time! Sefton encouraged his staff to be involved in RACI activities but was not actively involved himself.
Sefton was elected a Fellow of the Australian Academy of Science in 1966 and was actively involved in the work of the Academy until 1981. He was a member of the Board of Standards of the Australian Journals of Scientific Research (1968–1971) and Chairman (1972–1974). He was loyal to the journals, publishing nearly half of his papers in the Australian Journal of Chemistry. He was a member of the Academy’s Sectional Committee for Chemistry (1969–1973), including being Chairman (1971–1972). He was also on the Sectional Committee for Applied Physics and Chemistry (1971–1973), and for Applied Sciences (1978–1982). He was a Member of Council (1969–1972), a member of the Standing Committee for Scientific Information (1972–1978) and a member of the Standing Committee for International Relations (1979–1981).
When the Australian Government established the Australian Research Grants Committee in 1965, Sefton and Dr D. L. Ford (Chief Research Chemist, Union Carbide Australia Ltd) were the only non-university members. He remained a member of that Committee until 1970 when he was replaced by Dr N. K. Boardman.
Sefton had a keen eye for contradictions and mistakes in the published literature. His last paper (145) was a detailed analysis and refutation of the claims by a US scientist that ‘phantom activation volumes’ exist in certain organic reactions. His penchant for correcting mistakes did earn him a rebuke from Keith Sutherland in 1959. It started with a letter to the Sydney Morning Herald by Associate Professor R. C. Bosworth of the University of New South Wales on Tuesday 17 February 1959. Bosworth had calculated that if the world continued to burn coal and oil at the current rate, we would be asphyxiated by carbon dioxide in less than 1,000 years. Sefton and a colleague, H. G. David, wrote a quick response pointing out that Bosworth had grossly miscalculated the amount of oxygen in the earth and that there was no need for concern. They gave the CSIRO Division of Physical Chemistry as their address. Sutherland was quick to remind Sefton that he should not use the CSIRO address without permission!
Sefton’s legacy is his science. His first paper was published in 1951 and his last in 2004, 53 years later. In writing his case for promotion to Senior Principal Research Officer in 1957, Keith Sutherland summarized Sefton’s contribution succinctly: ‘Hamann has the ability to strip problems to a few essential features which, when investigated, clearly illuminate a wide group of phenomena.’
This memoir was originally published in Historical Records of Australian Science, vol.20, no.2, 2009. It was written by:
Numbers in square brackets refer to the notes, and numbers in brackets refer to the bibliography.
The authors thank Dr A. H. Ewald, Professor R. G. H. Prince, Dr A. F. A. Wallis and the Hamann family for their assistance.
Hamann, S. D., The Physico-Chemical Effects of Pressure. Butterworths: London, 1957. ix+246 pp.
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