Abstract The study of nuclear magnetic order in Copper is the most ambitious and difficult neutron scattering experiment ever performed at Ris⊘. Beside expensive hardware, approximately 50man-months of scientific work, 24 months of beam time and 10000 litres of liquid He had to be invested before we could even expect to discover whether the experiment would turn out to be either a great success or an utter failure. The undertaking was carried out by an international team consisting of Professor O.V. Lounasmaa's group from the Low Temperature Laboratory at Helsinki University of Technology, Professor M. Steiner's group at both the HahnMeitner Institut in Berlin and the Johannes Gutenberg University in Mainz, and the Ris⊘ group.