A shop assistant shows a customer a luminous flower in Selfridge’s department store, London. The flowers were designed to glow in the dark during wartime blackouts, helping people navigate streets safely amid enforced darkness. (1940) [2480×1724]

A shop assistant shows a customer a luminous flower in Selfridge’s department store, London. The flowers were designed to glow in the dark during wartime blackouts, helping people navigate streets safely amid enforced darkness. (1940) [2480×1724]

by StephenMcGannon