Stoney, George Johnstone (1826–1911), mathematical physicist and astronomer, was born 15 February 1826 at Oakley Park, Clareen, near Birr, King's Co. (Offaly), elder son among three children of George Stoney, landowner, and Anne Stoney (née Bindon Blood) of Crannagher and Rockforest, Co. Clare. The family derived from protestant settlers of the sixteenth and seventeenth centuries. His only brother was Bindon Blood Stoney (qv), chief engineer of the Dublin port and docks board. A happy childhood was spent at Oakley Park, where he was educated by tutors. During the time of the famine (1845–9), when land prices plummeted, the family property was sold to support his widowed mother and family. George and his brother went to TCD, where they supplemented their income by giving private grinds. In 1847 he was awarded second senior moderatorship in mathematics, receiving his BA the following year. That same year (1848) he was appointed first astronomical assistant to William Parsons (qv), 3rd earl of Rosse, at his observatory in Parsonstown (Birr Castle), where he also tutored Charles Parsons (qv) and his brothers. He competed unsuccessfully for a TCD fellowship (1851), coming third, but achieved second place and the Madden Prize (£300) (1852). He was rewarded later that year by an appointment – through the influence of his friend Lord Rosse – to the chair of natural philosophy (mathematics) at QCG, where he succeeded his TCD classmate Morgan Crofton. During his time in Galway he introduced the study of astronomy and applied physics to the curriculum.
In 1857 he returned to Dublin in an administrative capacity as secretary to the Queen's University in Ireland, again on the recommendation of Lord Rosse. He held the post until the college's dissolution (1882), when it was replaced by the Royal University, a solely examining body. He also acted as superintendent of the civil service examinations in Ireland until his retirement. During his twenty-five years as administrative secretary he contributed to university policy and was seen as liberal and non-sectarian. He was a strong advocate of higher education for women, which led him to move to London on his retirement (1893) for the sake of his daughters' university education. In his spare time during his working life he continued his scientific investigations at the RDS laboratory and later in London with the Royal Society.
His scientific interests were broad and he made contributions in a range of areas, particularly physical optics, solar physics and astronomy, atmospheric physics, acoustics, and molecular physics, as well as education. At Birr Castle he made astronomical observations on what was at the time the largest telescope in the world. He continued this interest in astronomy throughout his life and wrote several papers, from adjustments of instruments to more theoretical aspects, dealing with atmospheres of planets and particularly with the sun. From his analysis of the kinetic theory of gases he surmised that the interaction between the weight and velocity of a molecule and the strength of gravity of a planet indicates the presence of an atmosphere and its constituent gases. By this means he explained the absence of an atmosphere on the moon and of hydrogen in the earth's atmosphere, and concluded that water is unlikely to exist on Mars.
However, his most significant contribution to science was the coining of the term ‘electron’, the charge of the atom or unit of electricity, which arose out of his work on the kinetic theory of gases and spectroscopy (Scientific Transactions of the RDS (1891), 583). He was also the first to estimate the number of molecules in a cubic millimetre of gas, at room temperature and pressure (Philosphical Magazine, xxxvi, no. 4 (1868), 132–41). As a member of the committee of the British Association for the selection and nomenclature of dynamical and electrical units (1873) he contributed to the establishment of standard electrical measurements.
During his life he was an active member of several societies, including the RIA (elected 1856), and the RDS, where he was secretary from 1871 and vice-president (1881). As secretary he was a crucial negotiator at the time when the RDS handed over to the Irish state its library, natural history museum, botanical gardens, and school of art NCA(D) under the Dublin Science and Arts Museum Act, 1877. He was also involved in the negotiations to acquire the RDS Ballsbridge premises, and during his term of office the government consulted him on numerous issues – agriculture, fisheries, and railways. He was fellow (1861) and vice-president of the Royal Society (1898) and a foreign member of the Academy of Science, Washington, and the Philosophical Society of America. Among others responsibilities, he was a member of the joint committee of the Royal Society and Royal Astronomical Society on solar research. He was awarded an honorary D.Sc. from both QUB (1879) and TCD (1902), and was the first to receive the RDS Boyle medal (1899).
He had a large circle of friends and was remembered for his kindly and courteous nature and enthusiasm for science, which was ‘never failing and most infectious, longing to take one step into the unknown’ (Sci. Proc. RDS, ix (1899), 106). He was passionate about music and, though not a performer, published a number of papers on musical notation and sound. Towards the end of his time in Dublin he initiated the very successful chamber music recitals in the RDS, which continued for many years. He married (January 1863) his cousin Margaret Sophia, daughter of Robert Johnstone Stoney of Parsonstown (Birr); they lived at 89 Waterloo Road, Dublin. She died nine years later (1872) after they had two sons and three daughters, and he went to live first at Weston House, Dundrum (1874–8), and then at 3 Palmerston Park, Rathmines (1878). His elder son George Gerald Stoney (qv), whom he home-educated in his early years, was manager of Parsons Turbine works, Newcastle, and later professor at Manchester College of Technology (University of Manchester Institute of Science and Technology). His daughters Edith Anne and Florence Ada were respectively lecturer in physics at the London School of Medicine for Women and head of the electrical department, New Hospital for Women, London. His nephew George Francis FitzGerald (qv), the eminent mathematician, was son of his sister Anne Frances Stoney, who had married her cousin William FitzGerald.
After moving to London he lived first at Hornsey Rise, north London, before moving to 30 Chepstow Crescent, Notting Hill Gate, west London. In his latter years illness confined him to a single floor of the house, which was filled with books, papers, and scientific instruments, often self-made. He died 5 July 1911 at his home, and his ashes were buried in Dundrum, Co. Dublin. A portrait by Thomas Jones (qv), RHA, was presented by students of the Queen's University on its dissolution (1882) to the RDS, and now hangs in the council room. In NUIG a physics laboratory is named in his honour and a commemorative plaque hangs in the archway of the quadrangle.