In mid-October, a small crowd — including me — stood in the middle of a narrow road in Drumcondra, huddling into our coats against sporadic gusts of wind as we gazed at a neat red-brick terraced house.
To the right of the front window at 30 Dargle Road, an incongruous small curtain was mounted on the exterior wall. With a few gentle tugs, Trinity College Dublin provost Prof Linda Doyle pulled it back to reveal a new blue plaque commemorating the house that once belonged to the enigmatic Irish inventor and pioneering computer scientist, Percy Ludgate, a man far ahead of his time who remains mostly unknown in ours.
Inside that house, in the early years of the last century, Ludgate — only in his 20s — worked out the astonishing conceptual design of the world’s second computer. The first is now widely recognised — that’s the “analytical engine” developed by the English mathematician Charles Babbage from the 1830s onwards, assisted by his mathematician friend, Ada Lovelace.
Early historical accounts all presumed that over a hundred years, and two world wars, had passed before anyone anywhere successfully, knowingly or otherwise, followed in Babbage’s footsteps
— Prof Brian Randell
Though Babbage never managed to build the machine himself, a working model was eventually created at London’s Science Museum and another sits in the Computer History Museum in Silicon Valley. I’ve visited both and seen (and heard) them in operation — it’s quite a dramatic process involving an enormous, clattery construction of shining gears and cogs and moving parts.
“Early historical accounts all presumed that over a hundred years, and two world wars, had passed before anyone anywhere successfully, knowingly or otherwise, followed in Babbage’s footsteps,” Prof Brian Randell of the school of computing at Newcastle University, told us at the plaque launch. “But now we know otherwise.”
As Randell explained, Ludgate came up with a wholly original design using shuttles containing 21 sliding rods, controlled by a perforated paper tape. Unlike Babbage’s machine, Ludgate’s could perform straightforward multiplication and division. It also had some early features of modern computers, such as the ability to run subroutines.
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It is thanks to a small group of dedicated computer scientists that Ludgate’s achievement and importance are now historically acknowledged, even if he remains under-recognised in the public mind. In 1971, Randell wrote an early paper on Ludgate after reading Ludgate’s sole paper on his computer, published in the 1909 Scientific Proceedings of the Royal Dublin Society.
Spearheading much of the recent work on Ludgate is Trinity computer scientist Dr Brian Coghlan, who has worked hard to give Ludgate his rightful place in computing history. Along with Randell, he has co-edited a new book that gathers together a wide range of papers on Ludgate, and he maintains a collection of online Ludgate resources at TCD. He also organised the plaque’s launch but then, unfortunately, contracted Covid and was unable to attend.
Among those there on the day was Ludgate’s American descendant, his grand-niece Trish Gonzalez. Representatives from the Royal Irish Academy, the Royal Dublin Society, Engineers Ireland, the Irish Academy of Engineering, the Irish Computer Society, and the Irish Mathematical Society came to pay respects at the house on Dargle Road, too.
Also present were the first and the most recent recipients of TCD’s Ludgate Prize, given every year to recognise the finest student thesis from that year’s graduating class in computer science. The first recipient, in 1991, was Dr Steven Collins, who went on to co-found the successful gaming software company, Havok.
TCD student Mohamed Suliman, a Dubliner of Sudanese heritage, is the most recent (2021) recipient, for his thesis Timeline Probabilities, which is “all about temporal knowledge representation and reasoning”, he told me. I enjoyed chatting with him at the reception after the plaque unveiling and we connected again by email a few days later.
Winning the Ludgate Prize was a nice surprise, he says, because “the subject I chose was not an orthodox thesis topic for computer science (I had brought it up myself), and it took some time to find a supervisor who would take it on, so it was nice to be recognised for the work”.
He also enjoyed learning about Ludgate. “The prize’s namesake allowed for a nice lesson in Irish and computing history,” he says. I’d like to think such an unconventional innovator as Ludgate would be quite pleased that another unorthodox thinker received the prize bearing his name.
Imagine what Ludgate might have thought about much of the world these days owning a pocket computer in the form of a smartphone
Suliman is now in the second year of a PhD. “I’m focusing on the intersection between machine learning/AI and privacy, things like the security of these AI models and the [often private] user data used to train them,” he says. He’s about to submit a paper that shows it is possible to reconstruct user data from the AI models that predict what word a person is about to type next — “those three-word suggestions that appear above the keyboard on a smartphone”.
Imagine what Ludgate might have thought about much of the world these days owning a pocket computer in the form of a smartphone, taking up less space than a couple of his sliding rods and, thankfully, requiring no perforated tape (just think of the mess, otherwise).
And imagine what more Ludgate might have done, had he lived longer. He died from pneumonia at the young age of 39, just over 100 years ago in October 1922. The centenary also marks a welcome moment where ever more people are learning about him and recognise this Irish link in computing history.
