The detainees were mostly treated quite well. The guards had to obey the Geneva Conventions. Although there were some people who found it very difficult being kept there, many others found lots of things to do to keep themselves occupied. Letters, books, sports equipment and a printing press were all allowed into the camp and the detainees organised their own police force, magazine, library and postal service. Some of the detainees were young people who later became famous. They included the Canadian musician Ernest MacMillan who later became the conductor of the Toronto Symphony Orchestra. MacMillan had been on holiday in Germany to visit the Bayreuth Festival when war broke out. Charles Ellis and James Chadwick later became famous scientists. They used their time in Ruhleben to study. They were able to build a laboratory and do some experiments. There were famous footballers and athletes as well.