Allman, George Johnston (1824–1904), mathematician, was born 28 September 1824 in Dublin, a younger son of William Allman (qv), botanist. After a brilliant undergraduate career at TCD, he graduated in law as well as mathematics and went on to obtain (1853) the chair of mathematics at QCG, holding it until his retirement (1893). He contributed papers to scientific journals and articles on Thales, Pythagoras, and Ptolemy to the ninth edition of Encyclopaedia Britannica (1875–88). Most highly praised among his publications was History of Greek geometry from Thales to Euclid (1889), which threw new light on the rise and progress of geometry and arithmetic. Allman was a founder member of the Dublin Statistical Society; he became FRS in 1884. Like his lifelong friend John Kells Ingram (qv), he was a disciple of Comte, whose influence is said to have affected his teaching. Together with Ingram and the other leading Irish positivist, Henry Dix Hutton (1824–1907), Allman aligned with the English philosopher Richard Congreve (1818–99) in the positivist schism of 1877–8. Allman died 8/9 May 1904 at Farnham House, Finglas, Co. Dublin. His funeral was at St Nicholas church, Galway. He married (1853) Louisa (d. 1864), daughter of John Smith Taylor of Corballis, Co. Meath; they had a son and two daughters who survived him.
Ir. Times, 10 May 1904; Proceedings of the Royal Society of London, lxxviii (1906–7), obit., pp xii–xiii; DNB; Alumni Dubl. (1935); G. K. Peatling, British opinion and Irish self-government 1865–1925 (2001)