Henry Hennessy

Henry Joseph Hennessy (19 March 1826–8 March 1901) was an Irish physicist and Fellow of the Royal Society.

Life Born at Cork, Ireland on 19 March 1826, he was the second son of John Hennessy of Ballyhennessy, County Kerry, and his wife Elizabeth, daughter of Henry Casey of Cork; John Pope Hennessy was a younger brother of Henry's. Educated at Cork under Michael Healy, he as a Roman Catholic in the 1840s did not seek a university education, but took up the profession of an engineer.

In 1849 Hennessy was made librarian of Queen's College, Cork, and in 1855, on the invitation of John Henry Newman, he became professor of physics at Catholic University of Ireland. In 1874 he transferred his services to the Royal College of Science, Dublin, where he was appointed professor of applied mathematics. He was dean of the college in 1880 and again in 1888. Hennessy was made a member of the Royal Irish Academy in 1851, and was its vice-president from 1870 to 1873. He was also elected Fellow of the Royal Society in 1858. led to a request to report on the temperature of the seas surrounding the British Isles for the Committee on Irish Fisheries in 1870. He published also:

On the Study of Science in its Relation to Individuals and Society, Dublin, 1858; 2nd edit. 1859. On the Freedom of Education (a paper at the Social Science Congress, Liverpool, in 1858), 1859. The Relation of Science to Modern Civilisation, 1862.

Family Hennessy married Rosa Corri (1836-1926), youngest daughter of Hayden Corri. They had one daughter, Mary Rosa Hennessy (later Dashwood,1873–1949).