"to my old pals, sir Robert and lady Ball, astronomer royal, at the levee. Sir Bob, I said..."
Sir Robert Stawell Ball (1840 - 1913) was an Irish astronomer to Lord Rosse in 1865 and Irish Astronomer-Royal in 1874. In 1892 he was appointed Lowndean Professor of Astronomy and Geometry at Cambridge University. His lectures, articles and books (eg. 'Starland' and 'The Story of the Heavens') were popular and simple in style. 'The Story of the Heavens' is in Bloom's library.