ATD 97-118
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Hamilton had experienced at Brougham Bridge
William Rowan Hamilton (1805-1865)was an Irish mathematician, physicist, and astronomer who made important contributions to the development of optics, dynamics, and algebra. His discovery of quaternions is perhaps his best known investigation.
The discovery of quaternions reportedly occurred during a walk with his wife by the Royal Canal in Dublin. Upon having the inspiration for the formula, he promptly carved it into the bricks on the side of the canal. Wikipedia entry