Our Quaternion Walk
Dublin, 23 June 2002



We started at Dunsink Observatory on a bright Sunday, without fearing the "scattered showers" promised by the taxi driver who left us there.
    William Rowan Hamilton was the observatory director. He lived and worked there. The 16th of October 1843, he left these grounds for attending and presiding over a meeting of the Royal Irish Academy, in downtown Dublin. On his way, as he was passing by Broom Bridge over the Royal Canal, he discovered quaternions' fundamental formula.



Broom Bridge is charming,                                      
but most unimpressive.



In 1958, a plate was erected on the site, commemorating the discovery and displaying the fundamental formula:



Following the Royal Canal through the pathway, we arrived upon central Dublin half an hour later. Still no showers, scattered or unscattered.
Here, we are looking back at Broom Bridge.



Hamilton's destination was the Royal Irish Academy at 19 Dawson Street, in the center of Dublin. The building is still there. Hamilton climbed these very steps and went into the Meeting's Room.



Two days after our quaternion walk, we walked into the Academy. It is worth the visit. It has on permanent display the Irish oldest extant manuscript, the Cathach (c. A.D. 560-630 ). After waiting some minutes for the room to be free, we entered the Member's Room, where this picture of William Rowan Hamilton is hanging on the wall.


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Some links related to the Quaternions' Walk:
William Rowan Hamilton (1805-1865)
The Quaternion Walk at NUI Maynooth
Dunsink Observatory (travel directions)
Royal Irish Academy