During the nineteenth century, Britain became the first gaslit society, with electric lighting arriving in 1878. At the same time, the British government significantly expanded its power to observe and monitor its subjects. How did such enormous changes in the way people saw and were seen affect Victorian culture? To answer that question, Chris Otter mounts an ambitious history of illumination and vision in Britain, drawing on extensive research into everything from the science of perception and lighting technologies to urban design and government administration. He explores how light facilitated such practices as safe transportation and private reading, as well as institutional efforts to collect knowledge. And he contends that, contrary to presumptions that illumination helped create a society controlled by intrusive surveillance, the new radiance often led to greater personal freedom and was integral to the development of modern liberal society.