VERY LARGE BURST DUE TO HIGH ENERGY MUONS

Large muon detectors at 20 mwe underground were used to study bursts due to high-energy muons. About 11,000 bursts with more than 100 ionizing particles initiated in rock were observed. Experimentally observed frequency distribution of bursts as a function of size was compared with the size distribution calculated from theory. Approximate agreement was obtained. (A.G.W.)