Members of the team working with the Saclay/Ecole Polythechnique (Paris) 81-cm liquid hydrogen bubble chamber on the platform in the North experimental hall of the CERN Proton Sycnhrotron (PS). We can see Giovanni Borreani and Albert Werbrouck from the University of Turin, Adolf Minten from CERN and Philippe Briandet of the Ecole Polytechnique, Paris. Giovanni Borreani, adjusting one of the controls, is visiting CERN from the University of Turin. Making notes on the table in front is Albert Werbrouck, an American physicist also from the University of Turin. In the centre is Adolf Minten, a CERN staff member formerly at the University of Bonn, and standing on the right is Philippe Briandet of the Ecole Polytechnique, Paris.