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: 12 February 1921, Ireland
Died: 20 April 2006
Country most active: United States
Also known as: Kathleen McNulty, Kay Mauchly
Kathleen McNulty’s parents were James McNulty (1890-1977) and Anne Nelis (1892-1966). James McNulty was born in Creeslough in Donegal County, Ireland where his family had owned a large part of the hillside for generations. He was the youngest of his parents’ seven children. His father Patrick McNulty died in 1892 and his mother Catherine McNulty in 1902 so by age eleven he was brought up by his older brothers. He decided to follow one of his older brothers who became an apprentice stonemason in the United States, and sailed from Londonderry to New York arriving on 9 May 1909. In Philadelphia he trained to become a stonemason, but also became involved in Irish politics joining a group which was raising money for guns and ammunition to fight against British rule of Ireland. He returned to Ireland in 1914 in order to recover from typhoid fever and served as commandant of the Doe Battalion of the Irish Volunteers. He planned to marry Anne Nelis and they had an American style home built on her brother’s farm. They married on 1 February 1917. In early 1919 James McNulty was involved in an attempt to seize guns from the home of a protestant JP. James was shot and seriously injured; recovery was a slow affair.
Kathleen, the subject of this biography, had two older brothers Patrick John McNulty (1918-1986) and James Joseph McNulty (1919-2001). On 7 February 1921 Kathleen’s father was with a group of men who blew up a railway bridge causing a derailment in which fifteen British soldiers were injured. On the night that Kathleen was born, 12 February, he was arrested at his home and kept in Derry Jail. In July 1921 he was sentenced to five years penal servitude for “having alleged seditious documents.” In December 1921 he was one of about a dozen IRA prisoners who attempted to break out of Derry Jail. Two Royal Irish Constabulary guards were killed in the attempt. On 12 January 1922 he was released from prison and all charges were dropped. Three of his fellow prisoners who had been involved in the escape attempt were sentenced to death for the murder of the two guards but they were released in 1925. James decided to emigrate to America and went to prepare the way, leaving his wife and children in Ireland. In August 1923 he sailed from Londonderry to New York on the S S California arriving on 2 September. He went to Philadelphia where he built a house in Wyndmoor, a district of Chestnut Hill. He declared his intention to become a naturalised American citizen on 27 June 1924. The family, Annie, Patrick, James, Kathleen and her sister Anna Marie McNulty (1923-2003) sailed on the S S Columbia from Londonderry to New York arriving on 13 October 1924.
After two years in the house at Wyndmoor, the family moved to a larger home at 48 Highland Avenue in Chestnut Hill. The 1930 US Census shows the family to have increased with Cecilia Marguerite McNulty (1926-2014) and John Joseph McNulty (1928-1992) both being born in Philadelphia. Living with them are John McNulty, the oldest brother of James McNulty and 14 years his elder, and Hugh Nelis, Annie’s brother. The first is a labourer in the building trade, the second a labourer in gardening. They also have two lodgers, one an electrician in the building trade, the other a gardener.
Kathleen’s education was in Catholic Schools in the United States beginning in 1927. After seven years in her first school, she entered Hallahan High School, an all girls Catholic school.
After graduating from Hallahan High School in 1938 she began her studies at Chestnut Hill College for Women in Philadelphia where she was offered a scholarship:-
I had taken an academic course in high school. I had taken four years of mathematics, four years of English, four years of Latin, three years of French, and a year each of biology and chemistry. When I got to college and my counsellor asked me what I wanted to major in, I thought that since I was there on a scholarship, I would have to keep my marks up. The easiest way to do that was to take mathematics as a major. I loved it and found it fun and easy to do. I didn’t want to teach. I just wanted to do the maths puzzles. I took algebra, differential calculus, integral calculus, differential equations, different kinds of geometry, astronomy, and two years of physics. Originally, I intended to minor in physics. … I didn’t want to teach. I thought that business sounded like a good thing, so I changed my minor to business administration. Then I took courses in business, accounting, money and banking, and anything else that had to do with business.
She graduated from Chestnut Hill College in 1942.
Of course 1942 was in the middle of World War II and by this time the war was strongly affecting the direction of academic research. The United States was specifically directing its research schools and staff towards the war effort. The University of Pennsylvania’s Moore School of Engineering began putting on training courses for electronics and other disciplines as part of this war effort. They also began early research in the use of computers. The Ballistic Research Laboratory had been set up at Aberdeen, in Harford county, northeastern Maryland as part of the Aberdeen Proving Ground, a military weapons testing site which had been established in 1917 during World War I. The Ballistic Research Laboratory consisted of staff from the Moore School and staff from the Aberdeen Proving Ground using their expertise on joint projects.
After graduating Kay McNulty answered an advertisement by the Moore School of Engineering for “math majors” and she applied, was interviewed and was employed as a mathematician; she worked on preparing firing tables for guns. McNulty described the work which she did in the following way:-
We did have desk calculators at that time, mechanical and driven with electric motors, that could do simple arithmetic. You’d do a multiplication and when the answer appeared, you had to write it down to re-enter it into the machine to do the next calculation. We were preparing a firing table for each gun, with maybe 1,800 simple trajectories. To hand-compute just one of these trajectories took 30 or 40 hours of sitting at a desk with paper and a calculator. As you can imagine, they were soon running out of young women to do the calculations. Actually, my title working for the ballistics project was “computer”. The idea was that I not only did arithmetic but also made the decision on what to do next. ENIAC made me, one of the first “computers”, obsolete.
The ENIAC computer (Electronic Numerical Integrator and Computer) which McNulty refers to in the above quote was being constructed by John Mauchly and John Eckert in the Moore School of Engineering during the war years. It was designed for the specific task of compiling tables for the trajectories of bombs and shells to take over the calculations which McNulty and about 75 other women were carrying out. However the war had ended before the machine came into service but it was still used for the numerical solution of differential equations as intended. McNulty was one of six women who became operators of ENIAC making very substantial contributions to computer science, although it took many years before they received the credit which they deserve for their pioneering work. McNulty spoke about the first problem that ENIAC was given:-
… the very first day that the ENIAC was finally declared it is now ready to work, although it hadn’t been fully tested, our test will be the feasibility of the H bomb. It was a tremendous, tremendous problem that had been brought in from Los Alamos. It was Dr Fermi and Dr Teller’s problem, and it was the feasibility of the trigger which they had designed. So we put that problem on the ENIAC. Now, someone had asked us a little while ago about the tubes and the reliability of them. There were many tubes that failed, but the ENIAC was built in such a way that a tube did not have to generate a certain amount of power – This is a vacuum tube I’m talking about, which in those days were pretty large. They were about five inches tall, each one, and there were 18,000 in the ENIAC. Which generated a tremendous amount of heat and everything. These tubes were not operated full power. Any amount of power would turn them on. So they only operated in an on or an off position. If they were on at all, they transmitted the power. If they were off, they didn’t. And that was the basic thing. So when we first started to operate the machine, we found out that there were a number of tubes that had actually failed, and another bad solder joints that had gone on and so on. Once those things got ironed out, the machine was really quite reliable and it operated very well. So the problem that came from Los Alamos at that time, we did not program it. The physicists who came from Los Alamos had actually programmed it. They had studied all about the ENIAC because they had Top Secret clearance, and they were able to have access to these wiring diagrams before we did, even. So they were able to program it and we helped them, all of us girls (girls we were called in those days) helped them program it and help them run it. It took about two and a half months.
This first program run on the ENIAC was declared a success and it was announced that it would be demonstrated to the world on 15 February 1946.
Linde Lunney writes:-
The public launch of the ENIAC machine as the first general-purpose electronic digital computer took place on 15 February 1946, causing great excitement in the scientific and business communities, as the potential importance of such machines was already evident. The event, however, relegated the women programmers to the role of hostesses, and official reports and early histories of computing made no mention of female operators. Tellingly, as mid-century America reversed the gains made in wartime by women in employment, science and public engagement, some contemporary observers even regarded the women in the project as ‘refrigerator ladies’: models employed to stand elegantly in front of machines that they did not understand.
Petzinger describes the way that McNulty used ENIAC to solve differential equations after the construction of the machine was complete in February 1946:-
The first task was breaking down complex differential equations into the smallest possible steps. Each of these had to be routed to the proper bank of electronics and performed in sequence – not simply a linear progression but a parallel one, for the ENIAC, amazingly, could conduct many operations simultaneously. Every datum and instruction had to reach the correct location in time for the operation that depended on it, to within 15000largefrac{1}{5000}normalsize50001th of a second.
On 7 February 1948 McNulty married John Mauchly, one of the two designers of the ENIAC computer. She explained why marrying was an emergency:-
… when I first married John, and that was, he said, a great emergency. His mother was sick, his wife had previously died two years before that, and his mother was not well. His children didn’t have anybody much looking after them. And the housekeeper that he had hired to look after the children was about to have a baby and she was going to leave, and oh, he had so many compelling reasons why we should get married. So, anyway, we did.
Her parents, however, objected to the marriage:-
Her mother objected to the union on the grounds that Mauchly was not Irish or Catholic, was 14 years her senior, and was a widower with two children. On their honeymoon, he presented Kay with a cookbook, with the words: “You are our new cook.” While cooking and raising seven children, Kay continued, uncredited, to programme the new computers that her husband developed.
In fact Kathleen’s parents refused to attend their daughter’s wedding and only after the birth of her first child, Sally, did her mother relent and visit her. Kathleen and John Mauchly had five children, Sally (born 1949), Kathy (born 1951), Bill (born 1953), Gini (born 1954) and Eva (born 1958). Sally majored in mathematics for her first degree, was awarded a master’s degree in mathematical education and became a teacher. Kathy majored in biology and took a master’s degree in biochemistry. Bill became an electrical engineer, Gini studied languages and Eva studied music.
By the time of their wedding, John Mauchly had left the Moore School and soon was designing further computers in partnership with John Eckert. John and Kay Mauchly lived on a farm in Amber, Pennsylvania, and Kay continued to work with her husband on the design of computer programs for the later BINAC and UNIVAC computers. She contributed skills in software design to these projects which complemented her husbands expertise in hardware design.
After John Mauchly’s death, Kathleen gave many talks on his work:-
I learned how to construct a talk and began speaking at various functions. UNIVAC hired me to be their representative at various national sales meetings and other places. I gave the keynote address at the celebration of the 40th anniversary of the ENIAC, when we met Kathryn Kleiman. I always spoke as John’s widow, not as myself.
Some years after the death of her husband in 1980, she married the photographer Severo Antonelli and lived in Pennsylvania. She became a celebrity with many invitations to speak. She began to speak for herself, not simply as John Mauchly’s widow speaking about him:-
All the years I gave talks about the ENIAC, I always talked about it as John’s story, not my story. Although I mentioned that I had been an ENIAC Programmer, it was just in passing. I told of John’s part in the development of ENIAC, about BINAC and UNIVAC, and his companies. I wrote a monthly article about John Mauchly for a little bulletin for some computer club. A member of that club arranged for Jean Bartik, Kathe Jacoby and me to speak at Princeton about our experiences. I think that was the first time that I spoke for myself. … Betty Jean Bartik and I have given many, many talks together at universities and companies including IBM and Microsoft. … I love doing it, but I mainly talk about being there. We even gave the keynote speech for an awards banquet of ACM. I went with Betty when Northwest Missouri University named their computer museum after her.
The recognition of the work she and other women did was long in coming but eventually the importance of their work was acknowledged. Kay Antonelli was inducted into the Women in Technology International Hall of Fame in 1997. She was a keynote speaker at the Women In Technology International’s East Coast Summit in Boston in 1998. She received an honorary doctorate from Chestnut Hill College. A scholarship in computer science is named in her honour at the Letterkenny Institute of Technology in Ireland. A computer science building was renamed in her honour in Dublin City University in 2017.
Antonelli died of cancer at Keystone Hospice in Wyndmoor and her funeral was held in St Anthony’s Roman Catholic Church, Ambler.