Sir Robert Stawell Ball FRS (1 July 1840 – 25 November 1913) was an Irish astronomer[1] who founded the screw theory.

[3] and was educated at Trinity College Dublin where he won a scholarship in 1859 and was a senior moderator in both mathematics and experimental and natural science in 1861.

In 1874, he was appointed Royal Astronomer of Ireland and Andrews Professor of Astronomy in Trinity College Dublin at Dunsink Observatory.

[7] His work on screw dynamics earned him in 1879 the Cunningham Medal of the Royal Irish Academy.

[citation needed] His work, The Story of the Heavens, is mentioned in the "Ithaca" chapter of Ulysses.

[21] His lectures, articles and books (e.g. Starland and The Story of the Heavens) were mostly popular and simple in style.

[22] Their children were: Frances Amelia, Robert Steele, William Valentine (later Sir), Mary Agnetta, Charles Rowan Hamilton, and Randall Gresley (later Colonel).