The First Female Tech Entrepreneur

Guest-authored* blog from Mary Monro

Osteopath and author of Stranger In My Heart (Unbound 2018),

Mary has also written a novelised version of Dora’s story: Power On. More information here.

Dora on her wedding day, August 1935

Dora Metcalf (née Greene, 1892-1982) was a mathematician by training, though she came from a family of engineers and her own life’s work was in the application of maths. Her story is one of a courageous response to loss and dauntless resilience in the face of entrenched opposition to women in business.

Her father, George Greene, was a senior officer in the colonial administration of India and died of cholera when Dora was eight. (His own father, an engineer on the Vartry Reservoir scheme near Dublin, died in an industrial accident when George was six, leaving his mother destitute with fourteen children). Although both parents were Irish, Dora’s mother was determined to seek the best education for her three children and brought them to Bedford, where there were excellent schools for boys and girls.

Bedford High had been sending girls to university since the 1880s and provided Dora with a nurturing academic environment. From there she studied for an external degree in mathematics from London University, earning her BA in 1911 when she was nineteen. At first she took the well trod path into teaching, being appointed Junior Mathematics and Riding Mistress at exclusive Allenswood Academy in south London.

List of university successes 1887-1895, A History of Bedford High School, 1932, Ed. KM Westaway.

The outbreak of the Great War changed everything. Dora left teaching and fell in love with the son of old family friends from India. They became engaged as Hugh left for Gallipoli, but he was never to return, leaving Dora among the heartbroken multitudes of ‘surplus women’. To save herself from drowning in sorrow, she took a job as a comptometer operator in a munitions factory and soon saw the potential for these mechanical descendants of the abacus. She began training other women to use the machines and was asked to go to Belfast to introduce them into the shipyards.

Felt & Tarrant Comptometer, Model F.
Dimensions: 9-1/2″W x 14-1/2″D x 6″H Weight: 20 pounds. Manufactured: Chicago, USA, 1915-1920. From

As a member of the Anglo-Irish Ascendancy, Dora seems to have been acquainted with the entire elite of Ireland and lodged with the owner of the Workman, Clark & Company shipyard, George Clark. He had opened his shipyard when he was only nineteen and so, when Dora was asked to set up an office selling comptometers in 1916, when she was 24, he most likely encouraged her. Ireland was in a revolutionary ferment at that time and traditional roles were being upended, along with ideas on nationalism, land tenure, workers’ rights, Irish culture, education and health.

The business was a success and in 1917 she set up offices in Dublin and Cork. She lodged with Matilda Knowles in Dublin, a leading botanist whose apartment was the meeting place for Dublin’s intelligentsia. Visitors included inspiring women such as Dr Katherine Maguire and Dr Kathleen Lynn, who would be the founders of St Ultan’s Hospital for women and children. These fearless women contributed to Dora’s growing confidence in pushing back boundaries.

Matilda Cullen Knowles (1864-1933)
Dr Kathleen Lynn (1874-1955)

In the next few years Dora used her mathematical training to identify diverse uses for comptometers and created a growing market for them in the commercial and government sectors. She had impressive contacts but they needed persuading, partly because of her gender and partly because they lacked imagination in seeing how these machines could serve their businesses. Meanwhile in England Dora’s cousin, Everard Greene, had co-founded British Tabulating Machines (BTM) in 1907, adapting American Hollerith machines to the British market. His big break came with the contract to analyse the 1911 British census, setting BTM on a path to winning business across the British Empire.

The 1921 census for the island of Ireland was abandoned due to the civil war, but Dora had her sights on securing this prestigious contract when it was rescheduled. She founded the partnership of Calculating and Statistical Services (C&SS) in 1924, with Everard and a friend of hers called Sam Haughton. Everard provided technological backing with his tabulating machines and Sam, whom she had met at Matilda Knowles’ flat, was a leading light in the Irish linen industry. He was also an Orangeman and a Freemason, effortlessly inhabiting the corridors of power from which Dora was barred due to her gender. These two men gave Dora’s new business the masculine credentials she needed and the 1926 census for Northern Ireland contract was duly awarded to C&SS.

From this flying start, Dora built an international business based on tabulating machines, Comptometers and associated services. The services side was Dora’s particular speciality as it played to her mathematical strengths and salesmanship. In 1931 she began running the calculations for the Irish Hospitals Trust sweepstake, a contract that would earn C&SS a fortune over the years and lead Dora to a private audience with Pope Pius XI in 1933. In 1934 she joined BTM as Director of the Service Bureaux Division, building on her impressive achievements with C&SS in Ireland, which she continued to run.

Replica bombe machine at Bletchley Park.

In the Second World War, Dora was involved in nationally important work that she would keep secret for the rest of her life. BTM was asked to build the bombe machines for the codebreakers at Bletchley Park, known as Bureau B within BTM. They would make over 200 bombes, in spite of severe shortages of supplies and staff. Dora had excellent relationships with the various government supply departments, and she knew how to recruit and train the women operators, making her the obvious person to manage the contract. Maybe it was she who suggested that women would make good operators, an idea that was initially opposed.

But her vital role was cut short by ill health at the end of 1942 and she was forced to retreat to less stressful work. Feeling underappreciated, she slowly withdrew from BTM after the war to concentrate on C&SS in Ireland. Never, in her twenty years as a divisional director at BTM, and in spite of widely admired work for St Ultans Hospital’s BCG vaccination programme, did her name feature in the BTM magazine. The only record of her is a photograph taken by her husband (Captain John Metcalf, who became a Personnel Manager for BTM after WW2) of a successful fishing expedition.


The dawn of the electronic age in the 1950s was a new challenge for Dora, now in her sixties, and C&SS were responsible for introducing the first electronic computer to Ireland at the Irish Sugar Company in 1957. She eventually retired aged 70, and went with her husband to live in a house on the shore of Loch Morar, with no electricity, no running water and only accessible by boat. Swordland Lodge had been used as a training centre for the Special Operations Executive (SOE) in WW2 but it has proved difficult to verify any connection with the Metcalfs. At 78 Dora decided that perhaps it was time for an easier life and they moved to Otley in Yorkshire, where Dora died aged 90. She was my great aunt.

* Note from Blog editor, Dr Nina Baker: As so delightfully happens from time to time, Mary was put in touch with me because of our mutual interest in interesting women in technical fields. In this case, Mary’s subject is the intriguing story of her great aunt. As she obviously has that personal link I wanted her to tell this story, although I did manage to find some snippets about Dora that Mary had not yet seen.

We believe that Dora was probably the first woman in the UK to set up her own company in what would eventually morph from business machines to computers, although the latter were after her time. If you know different, do get in touch.

3 Comments Add yours

  1. Tony Angel says:

    A very interesting account. By coincidence a cousin of my mother was a bombe operator. She is on the Bletchley Park database and her daughter sent me a photo of her mother with the certificate and badge that the ones who were still alive received about 6 or 7 years ago at Bletchley.


    1. Terrific! What a lovely family connection to have.


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