Eureka! The Irish invention that helped to land a man on the Moon.
This plaque is by the Royal Canal at Broome Bridge. It’s far from Dublin’s beaten track, yet, it is a place of pilgrimage to those in the know, and hundreds gather to mark the anniversary every October 16th.
And what are they commemorating? A new type of algebra, invented here in a flash of inspiration in 1843.
Called ‘Quaternions’ (because the equation has four elements), it is used to describe things moving in three-dimensions, everything from computer graphics to communications satellites and, yes, the Apollo lunar missions.
Quaternions were ‘invented’ by Sir William Rowan Hamilton, Ireland’s greatest scientist, who lived and worked nearby in Dunsink Observatory. Hamilton was walking by the canal when he had his Eureka moment, and scratched his equation in a stone by the towpath. The plaque was unveiled in 1958 by a Hamilton devotee, the maths teacher turned politician, Éamon de Valera.
Retracing Hamilton’s footsteps is a lovely 40-minute canalside walk, though going in reverse, from Broome Bridge to Ashtown, means you end at a coffee shop. The annual walk each October 16th is a pleasant gathering with talks and a local street party.
- Wikipedia: William Rowan Hamilton
- NUI Maynooth: Annual Hamilton Walk
- Google Maps: Hamilton Walk Route
- Ingenious Ireland: Quaternions by the Royal Canal Free Audio Podcast (For those who can’t make the annual walk — or prefer to sit and listen — we’ve made a podcast tour from the 2011 gathering, complete with the ballad of William Rowan Hamilton, and stories of canal wildlife and engineering)
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- Plaque at Broombridge – photo by Ingenious Ireland
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- Sir William Rowan Hamilton – photo courtesy of Ingenious Ireland
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- A crowd gathered at Broombridge for the Hamilton Walk – photo by Ingenious Ireland
Written by Mary Mulvihill
A Dubliner, and an award-winning heritage writer, Mary wants more people to know about Ireland’s hidden history – from the many inventions and discoveries made by Irish scientists and engineers, to the Hill of Tara, which most Irish people have never seen. You’ll find her tours, audio guides and books at IngeniousIreland.ie. Mary’s Tips | Website
- Broome Bridge and Sir Hamilton’s Eureka Moment: Cabra, Co Dublin - February 27, 2013
- Exploring the Hill of Tara – Sacred Well, Sheela-na-gig, and Sloping Trenches: Tara, Co Meath - February 25, 2013
