The '80-inch' (200 cm) liquid hydrogen bubble chamber at the Brookhaven National Laboratory on Long Island, New York, in 1965. The stainless steel chamber is almost completely obscured by the surrounding magnet coil, the magnet yoke & the equipment to expand the chamber & keep the liquid hydrogen cool. The whole assembly weighed 450 tonnes & was 7.2 m high. The man is removing 1 of 3 automatic cameras which photographed the tracks of subatomic particles in the chamber. The beam of incoming particles from Brookhaven's AGS acceler- ator entered the chamber through the vertical rectangular 'window' to the lower right of centre.