Delegates attending the 7th Solvay Physics Conference in October 1933. The conferences were initiated by Belgian chemist and industrialist Ernest Solvay (1838-1922). As the signatures around the edge show, the attendees were the great men and women of physics in the 1930s. Those present included such luminaries as P M S Blackett (1897-1974), E Bauer, James Chadwick (1891-1974), Marie Curie (1867-1934) and her daughter Irene Joliot-Curie (1897-1956), Paul Langevin (1872-1946), Lise Meitner (1878-1968) and Ernest Rutherford (1871-1937).
© Science Museum / Science & Society Picture Library