Sir William Rowan Hamilton

Hamilton, Sir William Rowan, mathematician and astronomer, was born in Dublin, 9th August 1805, His father was an attorney; his mother was related to Hutton, the mathematician. Intended for an Indian appointment, he was, when a mere child, sent to study with an uncle at Trim. At four he had made some progress in Hebrew, and in the two succeeding years he acquired the elements of Greek and Latin. At the age of fourteen he was familiar with the rudiments of Hebrew, Latin, Greek, French, Italian, Spanish, German, Syriac, Arabic, Sanscrit, Hindustani, and Malay, and had written a letter in Persian to the Persian ambassador on his visiting Dublin.

In mathematics he was almost self-taught. Entering Trinity College in 1822, he carried everything before him, and had mastered Newton's Principia, the Differential Calculus, and La Place's Mecanique Celeste before he was nineteen. A paper containing original researches on curves of double curvature, and a memoir on caustic curves, read before the Royal Irish Academy in 1824, placed him in the front rank of scientific Irishmen. The astronomers of Europe were somewhat astonished when, in 1827, a young man who had not attained the age of twenty-two stepped at once from the position of an undergraduate to that of Andrews Professor of Astronomy and superintendent of the Observatory at Dunsink, near Dublin, especially as he was not known to have displayed any talent for practical astronomy or observing.

Until his marriage in 1833, his sisters, women of uncommon abilities, resided with him at the Observatory, Dunsink. He early produced his great work on The Theory of Systems of Rays, "which with its supplements is regarded as of the highest importance in relation to the geometry of optics. Chasles spoke of it as 'dominant toute cette vaste theorie.' Starting from the fundamental idea that light, whatever be its cause or constitution, must be amenable to the principle of least action (nature's economy in using up force), he arrived at most important deductions relating to reflection and refraction. One of his discoveries, literally made upon paper, was that of conical refraction, a thing neither known nor surmised by practical experimenters in optics." This discovery was first verified experimentally by Rev. Humphrey Lloyd. Mr. Hamilton was knighted by Lord Mulgravein 1835, on the occasion of the first meeting in Dublin of the British Association. In 1837 he was elected President of the Royal Irish Academy; of which, from 1832, he was one of the most active members.

His works on General System of Dynamics, Calculus of Quaternions, and his various contributions to philosophical transactions, besides stores of mathematical research left behind in MS., and to which it has been said the scientific world has not yet come up, are all monuments of his amazing genius and abilities. His Calculus is considered by mathematicians to be of great scope and power; it has been illustrated and developed since his death by Professor Tait of Edinburgh.

He declined becoming a member of the Royal Society on account of some conditions incident to membership. Poetry had a great charm for him — he numbered amongst his friends Coleridge, Southey, Wordsworth, and Mrs. Hemans, while his own poetical productions are of some value, "more, perhaps, as beautiful emanations of his character, evidencing the strength and generousness of his affections, and the loftiness of the aspirations and communings of his spirit, than as works of poetic art." A beautiful ode commencing "O brooding spirit of wisdom and of love" is given in his memoir in the Dublin University Magazine. He had little love of money, and was content to spend his days in the Observatory at Dunsink, on a small salary. He appeared last in public at the Dublin Exhibition of 1865, and died the 2nd of September in the same year, aged 60. His sister Elizabeth Mary in 1838 published a volume of poems dedicated to him.


40. Biographical Division of English Cyclopaedia, with Supplement: Charles Knight, 7 vols. London, 1856-'72.

116. Dublin University Magazine (19). Dublin, 1833-'77.

233. Manuscript and Special Information, and Current Periodicals.