Under the auspices of the International Union for Pure and Applied Physics, an international conference on high-energy accelerators and instrumentation was held at CERN between September 14 and 19, 1959. Some 340 participants to the Conference including 30 scientific secretaries from CERN, found space in the Main Auditorium. In addition the Council Chamber seated another 120 participants. These were able to watch the proceedings in the auditorium through closed-circuit television. English was the official language of the Conference but translators were available for the Russian language. Participants invited included about 80 scientists from the United States, 40 from the USSR, 75 from the rest of Europe and 40 from other parts of the world.