This biography, written by J J O’Connor and E F Robertson, has been republished with permission from the School of Mathematics and Statistics at the University of St Andrews, Scotland.
Born: 15 July 1897, United Kingdom
Died: 29 September 1982
Country most active: United Kingdom
Also known as: NA
Letitia Chitty was the daughter of Herbert Chitty (1863-1949) and his wife Mabel Agatha Bradby (1865-1944). Herbert Chitty, born 13 January 1863 in Marylebone, London to Joseph William Chitty and Clara Jessie Pollock, became a barrister at law. He married Mabel Agatha Bradby on 9 August 1890. Mabel Bradby, born 2 May 1865 in Harrow on the Hill, Middlesex, was the daughter of Edward Henry Bradby, a clergyman and headmaster of Haileybury School, and his wife Ellen Sarah Johnson. Herbert and Mabel Chitty had three children: Christopher Chitty (1893-1953); Letitia Chitty (1897-1982), the subject of this biography; and Patience Penelope Chitty (1904-1988). Several of the references give five children and name two other girls, Jessie Elizabeth Chitty and Helen Louisa Chitty. We cannot find any evidence for these two being Letitia’s sisters, and certainly at the time of the 1911 census there are only three children in the family.
In 1907 Herbert Chitty, Letitia’s father, became bursar of Winchester College but he had broad interests being also an antiquary and genealogist. Letitia, therefore, grew up in a well-off family; at the time of the 1911 census the family were living at 51 Campden House Road, Kensington, a house with ten rooms, and they had three servants, a nurse, a cook and a house parlour maid.
Letitia was privately tutored and attended Kensington High School between 1903 and 1916. This School had opened in 1873 as Chelsea School founded by the Girls’ Day School Trust, in fact it was the first of the Trust’s schools. It became Kensington High School in 1888 when it moved to Lytham House, St Alban’s Grove, Kensington. This independent school was able to offer girls a high quality education and prepare them for university studies. When Letitia Chitty studied there the Head was Miss Ethel Home who filled this role from 1900 to 1931:-
In 1900 we had the advantage of appointing as Headmistress Miss Ethel Home, a lady whose mathematical attainments are matched, as is so often the case, by an aptitude for music, which amounts in her case to genius, a word often misapplied, but here used appropriately.
Having gained from a strong mathematical education at Kensington High School, Chitty was admitted to Newnham College, Cambridge, in 1916 to study mathematics. World War I had started in 1914 so Britain was at war when she began her studies. She took the examinations for Part I of the mathematical tripos in 1917 but then was given leave to undertake war work with the Admiralty.
At the Admiralty Air Department she was involved in the development of aircraft. The first flight by the Wright brothers in 1903 had only lasted a few seconds but the development was rapid and quickly the potential of aircraft for military use was realised. Soon after World War I began in 1914, aircraft with guns were in combat. But the science was new and it was important to understand how materials acted to the stress of flying and the vibration caused by the propellers. She later recalled:-
There were no programmes, no calculating machines … we relied upon our slide rules and arithmetic in the margins … Lives were at stake and we couldn’t afford to let anything go through wrong.
Chitty worked at the Admiralty Air Department with Alfred John Sutton Pippard (1891-1969) on a mathematical investigation of stress analysis for the experimental planes being built. She also worked with Richard Vynne Southwell (1888-1970) at the Admiralty Air Department. She impressed with:-
… her astuteness in research, and her capacity to see problems, work out solutions, and to apply her mathematical expertise to work in a creative but uncomplicated way.
Chitty found the work she was doing at the Admiralty Air Department to be exciting and she was encouraged to continue to work in this area by Pippard and others. After the war ended she returned to Newnham College, Cambridge, in 1919 but rather than complete her degree by continuing to study the mathematical tripos, she decided to switch to the mechanical sciences tripos. She graduated with First Class Honours in 1921, becoming the first woman to achieve this distinction. Perhaps we should indicate that to say she ‘graduated’ is not quite true since at this time women were not included in the degree ceremony lists, but simply received a certificate saying they were entitled to a titular degree of B.A.
After her achievement at Cambridge, Chitty returned to work at the Air Ministry as a research assistant in 1922. In the final stages of World War I, the Admiralty Air Department designed a heavily armed airship, the R 38, intended to patrol and escort ships. When the war ended in 1918 construction had not started, but the R 38 was built and sold to the United States Navy in October 1919. A structural failure caused it to crash in August 1921 with the deaths of 44 of the 49 crew. Chitty worked as an assistant of Richard V Southwell for the Airship Stressing Panel which at that time was highly involved in the structure of the R 100 and R 101 airships, trying to make sure that the structural failure which had occurred with the R 38 was not repeated. She also worked with Southwell on the theory of fluid flow and on the structure of frames, particularly those to support bridges. She published two papers co-authored with R V Southwell, namely On the problem of hydrodynamic stability. I. Uniform shearing motion in a viscous fluid (1930) and A Contribution to the Analysis of Primary Stresses in the Hull of a Rigid Airship (1931). The first of these has the following introduction:-
Except in a few very simple cases, the equations which govern the motion of a viscous fluid have so far defied analysis. Their difficulty comes mainly from the fact that they are not linear, so that the principle of superposition cannot be employed, as in many branches of mathematical physics, to construct solutions by the method of series or of singularities. For the same reason the flow pattern in the neighbourhood of a moving body must alter when the speed of the body is changed, and it follows that any exact determination of the pattern will be restricted to some definite speed. As a matter of fact, no precise determination of this kind exists, except in cases where the motion is indefinitely slow. But the form of the equations gives no reason for doubting the possibility of “steady” motion (in which the velocities are functions only of position) in every case of flow past fixed and rigid boundaries. Now in experiment it is found (unless the velocities are very small) that eddying or periodic motions always occur. Thus the conclusion seems inevitable that a steady motion may become unstable as the rate of flow is increased, in the sense that accidental disturbances, if of suitable type, will persist.
The occurrence of eddies (or of “turbulent” motion) is intimately related with the important problem of the resistance of fluids, and it is therefore not surprising that the question of hydrodynamic stability has attracted much attention. Fairly obvious lines of investigation are suggested by the cognate theory of elastic stability. Starting from a known solution for steady motion, we imagine a disturbance to have been effected by some cause which it is not necessary to specify, and we examine, in the light of the general equations, the history of the disturbance after it has become “free.” The steady motion is judged to be stable if we can show that every disturbance, whatever its type, tends ultimately to vanish, and neutral or unstable if any type is found to persist or to increase. Since the general equations of motion are not linear, the question of stability may depend upon the scale of the disturbance; but if the disturbance is assumed to be infinitesimal (as is customary in elastic problems), we may omit infinitesimals of the second order from the equations which govern the disturbed motion, and then the history of the disturbance (within the assumption stated) is independent of its magnitude.
On 1 October 1933 Alfred Pippard was appointed as head of the Civil Engineering Department at Imperial College, London and in the following year Chitty joined him in Imperial College when she became his Research Assistant:-
Thus was resumed an association which began in 1917 and continued from 1934 until Pippard’s death [in 1969].
Pippard had been impressed with Chitty when they worked together at the Admiralty Air Department and he had invited her to be his assistant at Imperial College. Also in 1934 Chitty was elected a Fellow of the Royal Aeronautical Society, the first woman to he awarded this honour.
The topics that Chitty worked on are perhaps best illustrated by listing some of the papers that she wrote jointly with Pippard over the next few years: The stresses in a disk wheel under loads applied to the rim (1936); The mechanics of the voussoir arch (1936); and On an experimental method for the solution of plane stress problems (1936). The ‘voussoir arch’ work was at the request of the Building Research Station and the paper begins:-
In spite of the antiquity of the voussoir arch and the extensive use to which it has been put, the theory of its behaviour never appears to have been adequately examined; although there is a considerable literature dealing with its design, the methods suggested are largely empirical and do not take into account the essential features of the mechanics of the structure. With the object of throwing some light on the problem and, if possible, of obtaining a more rational basis of design, work has been in progress for some time in the Civil Engineering Department of Imperial College of Science and Technology, and the present paper describes the results obtained during the first stage of the research.
World War II began in 1939 and the Admiralty requested that she be allowed to work for them investigating stresses in submarine hulls resulting from explosions. The Ministry of Supply also called on her expertise to undertake both mathematical and experimental investigations while the Ministry of Home Security and the BBC also sought her expertise. She was, however, still involved in research at Imperial College and took on a larger role there in 1943 when she was appointed as a Lecturer in Civil Engineering. Despite these extra duties, Chitty was still able to publish research papers during the war. For example with Pippard she published Repeated load tests on a voussoir arch (1941), The stresses in an extensible suspension cable (1942) and Some problems presented by cable bracing (1945). She also published single author papers such as Modern experimental methods in connexion with the design of statically indeterminate structures (1944).
In 1946 Pippard proposed Chitty for membership of the Institution of Civil Engineers. Given her publication record and the number of different organisations which had sought her expertise, she should have been welcomed into the Institution but, of course, there was a prejudice against women engineers which had to be overcome. There was also the problem that she had no higher degree. Pippard wrote:-
Miss Chitty’s work throughout a lifetime of research has been distinguished by its methodical approach, its thoroughness and meticulous accuracy and a lively appreciation of the needs of the designer.
Twelve of Chitty’s papers were included with the proposal and the fact that she had been awarded four Telford Premium Medals for papers co-authored with Pippard was noted. The proposal was successful and in 1947 she became a fellow of the Institution of Civil Engineers.
She continued to publish important papers, for example a single authored paper On the cantilever composed of a number of parallel beams interconnected by cross bars (1947) and with Pippard, Experiments on the plastic failure of cylindrical shells (1948)), The effects of propping an arch (1948), and A study of the voussoir arch (1951).
Another major project that she undertook is described:-
In 1951 the civil engineering firm of George Binnie was contracted the Iraq government to build the Dokan dam in a tributary of the Tigris river and asked Professor Pippard and Letitia Chitty to look at the stresses involved. They developed a stress analysis technique using relaxation methods and a rubber model to verify the design form, in an important on the conventional trial load method then in general use. Their work resulted in a single curvature arch dam of single curvature to suit the profile of the gorge.
Along with several co-authors, they published The Experimental and Mathematical Analysis of Arch Dams, with Special Reference to Dokan in 1956. She continued to work on several projects, particularly on dams for the Arch Dams Committee of the Institution of Civil Engineers. She presented her work on dams to the international symposium of the Institution on arched dams in 1968. For the remarkable series of papers she had published, beginning in 1936, and particularly for her work on dams, the Institution of Civil Engineers presented her with their Telford Gold Medal in 1969:-
The last meeting [Alfred Pippard] attended at the Institution of Civil Engineers, on 21 October 1969, gave him particular pleasure. It was the occasion on which Miss Chitty received the Telford Gold Medal.
In fact Chitty had retired from her lectureship at Imperial College in 1962. This did not prevent her continuing to work at the College and she was made a fellow of Imperial College in 1971. She was also an associate of Newnham College, Cambridge, from 1927 to 1943 and then a second time from 1958 to 1970.
From the description of Chitty’s career we have given above, it might appear that she devoted her entire energies to mathematical theory and to experimentation in civil engineering. There was, however, so much more that this remarkable person had to give:-
A colleague of Letitia’s, Michael Carlile, remembers her eccentricities, in later life, such as carrying around a large shopping basket with a cat in it, sometimes it shared this with her knitting. She continued to attend the then annual University Teachers Christmas party for the children of staff on her own, long after her nieces and nephews had outgrown them: Letitia was still hugely entertained by the conjuring acts.
Yet she would attend the evening soirées at the Royal Institution and be fully engaged with the scientific discourse given at the meeting. She was fluent in seven languages, travelled greatly and had a wide interest in the arts and history, besides botany and was a great draughtsman.
Earlier in her life, during World War II, she had combined her love of travel and of botany in writing the book Abroad. An alphabet of flowers. With Illustrations: a Book of Flowers and Travel, first published in 1945 with a second edition in 1948. Here is an example taken from the book:-
Do you know that kind of flower vase which makes one think: “What in the world could I put in this, which wouldn’t at once look vulgar?” Why vulgar, and what would it mean quite, I don’t exactly know, and yet I’ve experienced that feeling and so, I expect, have you. Flowers are never vulgar, yet even flowers may fail to redeem the vase they are placed in and harmonise the whole.
Now this was a blue and white vase which my mother had bought in Tarragona. It bore a very crude white ground, there was nothing refined or delicate about it, none of that delicacy associated with the pottery from Talavera, near Madrid. Still, surely something could be done with it. I just must see what I could do, so my father and I set out for a walk to do it.
Of course there was no difficulty. It was local and knew what it was about, and a bunch of local wild flowers looked perfectly glorious and flamboyant in it: yellow Iris from the river, brilliant blue Anchusa, scarlet Poppies, and, to knit all together, great heads of gold green Spurge, or as the Botanists prefer, EUPHORBIA – great panicles (that’s the word) of golden yellow and green. The whole combination made a perfectly glorious vase of flowers which lit up and entranced our room.
Chitty also achieved fame outside the academic world, being interviewed by Vogue Magazine in her later years. She died at the age of 85:-
Chitty, who did not marry, died on 29 September 1982 at Ridgemead House nursing home, Englefield Green, Surrey, of senile myocardial degeneration and senile dementia, and was cremated at Woking crematorium. A memorial service was held at Holy Trinity, Prince Consort Road, London. Awards were created to commemorate her name and achievements at Imperial College and at Newnham College, Cambridge.