John Savill Vaizey, Dictionary of National Biography… (1892)
“ Ker was an ardent advocate of popular education, and of the diffusion of literature and art. Charles Knight, in ‘Passages of a Working Life,’ ii. 120, 121, says that he was ‘the most fertile in projects of any member of the committee’ of the Society for the Diffusion of Useful Knowledge, and suggested many publishing schemes apart from the society. ”
