G.P.S. Occhialini 1907-93

G.P.S. Occhialini, a legendary figure for all who remember the very beginnings of cosmic ray particle physics, died on 30 December. Born on 5 December 1907 in Rossombrone, near Urbino, he studied in Florence. Here he met Bruno Rossi, whom, although only two years his senior, he always regarded as a master. In 1932 Occhialini went to Cambridge where he worked with P.M.S. Blackett. They invented and perfected the counter-triggered Wilson chamber technique, recording cascade showers which confirmed the existence of the positron, discovered slightly earlier by Anderson, and demonstrating its symmetry with the electron