 He was an associate of Tom Roberts, Rupert Bunny and Bertram Mackennal, and for a time worked for the Adelaide Photographic Company.In 1873 Cook went to London, and from 1875 to 1926 was a constant exhibitor at the Royal Academy.In 1904 he published a pamphlet, "Anarchism in Art and Chaos in Criticism", which was followed in 1924 by "Retrogression in Art and the Suicide of the Royal Academy", an attack on all un-academic painters from Manet onwards.