Cavendish Laboratory : Cloud chamber tracks obtained by Chadwick
Cavendish Laboratory
<p style='text-align: justify;'>Photograph of tracks of α-particles from thorium showing two groups of ranges, 8.6 and 4.8 cms in air. The large number of tracks all radiated from the source just below the picture. The investigator was J. Chadwick. See Plate II, Fig. 3, Radiations from Radioative Substances, Rutherford, Chadwick and Ellis, 1930. Cambridge University Press.</p>