George Salmon (b. in Dublin 1819, d. 1904), like the last mentioned subject, was, at the time of his death, Provost of Trinity College, Dublin.  Besides theological writings, he contributed much to mathematical science, especially in the directions of conic sections, analytic geometry, higher plane curves, and the geometry of three dimensions.  He was a Fellow of the Royal Society, and received the Copley and Royal medals, as well as distinctions from many universities and learned societies.

John Casey (b.  Kilkenny 1820, d. 1891), F.R.S., was educated at a National School and became a teacher in one in later years.  Entirely self-taught as a mathematician, he raised himself from the humble position which he occupied to be a university professor (in the Catholic University of Ireland, and afterwards in the Royal University), and earned the highest reputation as one of the greatest authorities on plane geometry.  He was a correspondent of eminent mathematicians all over the world.

Henry Hennessey (b. in Cork 1826, d. 1901), F.R.S., was also a professor in the Catholic University of Ireland and afterwards in the Royal College of Science in Dublin.  He was a writer on mathematics, terrestrial physics, and climatology.

Benjamin Williamson (b. in Cork 1827), F.R.S., is a Senior Fellow of Trinity College, Dublin, and a distinguished writer on mathematical subjects, especially on the differential, integral, and infinitesimal calculuses.

Sir Joseph Larmor (b. in Antrim 1857), F.R.S., was educated at Queen’s College, Belfast, and in Cambridge, in which last place he has spent his life as a professor.  He now represents the University in parliament and is secretary to the Royal Society.  He is well-known for his writings on the ether and on other physical as well as mathematical subjects.

ASTRONOMERS.

William Parsons, Earl of Rosse (b. in York 1800, d. 1867), F.R.S., was a very distinguished astronomer who experimented in fluid lenses and made great improvements in casting specula for reflecting telescopes.  From 1842-45 he was engaged upon the construction, in his park at Parsonstown, of his great reflecting telescope 58 feet long.  This instrument, which cost L30,000, long remained the largest in the world.  He was president of the Royal Society from 1848 to 1854.

Sir Howard Grubb (b. 1844), F.R.S., is known all over the world for his telescopes and for the remarkable advances which he has made in the construction of lenses for instruments of the largest size.

Sir Robert Ball (b. in Dublin 1840, d. 1913), F.R.S.  Originally Lord Rosse’s astronomer at Parsonstown, he migrated as professor to Trinity College, Dublin, and subsequently became Lowndean Professor of Astronomy at Cambridge.  He was a great authority on the mathematical theory of screws, and his popular works on astronomy have made him known to a far wider circle of readers than those who can grapple with his purely scientific treatises.