John Hewitt Jellett, Irish mathematician whose career is spent at Trinity College Dublin (TCD), where he rises to the rank of Provost, dies in Dublin on February 19, 1888. He is also a priest in the Church of Ireland.
Jellett is born at Cashel, County Tipperary, on December 25, 1817, the son of Rev. Morgan Jellett and his wife Harriette Townsend, daughter of Hewitt Baldwin Poole of County Cork, by his wife Dorothea Morris. He is the eldest brother of Hewitt Poole Jellett, Serjeant-at-law (Ireland) and Chairman of the Quarter Sessions for County Laois, and of the Venerable Henry Jellett, Archdeacon of Cloyne. He is educated at Kilkenny College and at TCD, where he becomes a fellow in 1840.
Jellett marries his cousin on his mother’s side, Dorothea Charlotte Morris Morgan, daughter of James Morgan, on July 7, 1855. The marriage produces seven children. His son, William Morgan Jellett, is a member of the Parliament of the United Kingdom and is the father of the celebrated artist Mainie Jellett, and of Dorothea Jellett, director of the orchestra of the Gaiety Theatre, Dublin. Another son Henry Holmes Jellett is a civil engineer in British India. His daughter Harriette Mary Jellett is the wife of the noted Irish physicist George Francis FitzGerald. Another daughter Eva Jellett is the first woman to graduate with a degree in medicine from Trinity, and goes on to practice as a doctor in India.
Jellett graduates B.A. in mathematics in 1837, M.A. 1843, B.D. 1866, and D.D. 1881. He is ordained a priest in 1846. In 1848 he is elected to the chair of natural philosophy at TCD, and in 1868 he receives the appointment of commissioner of Irish national education.
In 1851 Jellett is awarded the Cunningham Medal of the Royal Irish Academy for his work on the “Calculus of Variations.” The society later elects him their president, a position he holds from 1869 to 1874.
In 1870, on the death of Dr. Thomas Luby, Jellett is co-opted a Senior Fellow, and thus a member of the Board of TCD. William Ewart Gladstone‘s government in February 1881 appoints him provost of Trinity. In the same year he is awarded a Royal Medal by the Royal Society.
After the disestablishment of the Church of Ireland by the Irish Church Act 1869, Jellett takes an active part in the deliberations of the general synod and in every work calculated to advance its interests. He is an able mathematician, and writes A Treatise of the Calculus of Variations (1850), and A Treatise on the Theory of Friction (1872), as well as several papers on pure and applied mathematics, articles in the Transactions of the Royal Irish Academy. He also writes some theological essays, sermons, and religious treatises, of which the principal are An Examination of some of the Moral Difficulties of the Old Testament (1867), and The Efficacy of Prayer (1878).
(Pictured: “John Hewitt Jellett,” oil on canvas by Sarah Purser)