Marble has been selected as the target material for the experiment (WA18). It will study neutral current interactions on the one hand, and on the other will measure the polarization of the muons produced by neutrino interactions in the detection system of experiment WA1, which is installed immediately in front of WA18. The new experiment is thus taking its place in the West Area Neutrino Facility (WANF) in the counter experiment building in between the bubble chamber buildings which house BEBC and Gargamelle. One sees here transport of part of the futur calorimeter from building 186 to 182.