The British physicist Patrick M. S. Blackett (1897-1974) used a modified Wilson cloud chamber to obtain the first photographs of the tracks left by the particles involved in a nuclear disintegration as well as those produced by showers of cosmic rays.

Patrick Maynard Stuart Blackett was born on November 18, 1897, in London, England. At age 13 he entered naval training school, graduating four years later at the outbreak of World War I. He served in the Royal Navy as an officer throughout the war, participating in the Battles of Jutland and the Falkland Islands. In 1919 Blackett resigned his naval commission to study physics at Cambridge University. There he met, and eventually worked under, the physicist Ernest Rutherford.

The opening of Blackett's scientific career coincided with two important developments in physics. The first was the work of C. T. R. Wilson, who had built a small cloud chamber in which the...