Charles Jasper Joly (27 June 1864 – 4 January 1906) was an Irish mathematician and astronomer who became Royal Astronomer of Ireland.[1][2] He was an important figure in the study of quaternions.[3]
Joly was born at St Catherine's Rectory, Hop Hill, Tullamore, County Offaly, the eldest of six children of Rev. John Swift Joly (1818-1887) and Elizabeth Slator (1835-1904). He was educated at Galway Grammar School and later at Trinity College Dublin,[4] where he took a fellowship in 1894. He became Andrews Professor of Astronomy at Trinity College.[4]
In 1897, he was appointed Royal Astronomer of Ireland and he took up his new position at Dunsink Observatory. He was secretary of the Royal Irish Academy and a Fellow of the Royal Astronomical Society. He was made a Fellow of the Royal Society in 1904.[1]
In 1900 he went on the RIA/RDS eclipse expedition to Spain and later took part in the British Association visit.[3]
He and his daughter contracted typhoid shortly after his return due to infected milk.[4] He died at his residence in Dunsink, County Dublin, in 1906.[5]
Charles Joly published his articles in Royal Irish Academy journals, generally the Transactions, but as indicated below, in Proceedings of the Royal Irish Academy in 1897, 98, and 99: