1. The Sun. Hydrogen Spectroheliogram. (J. Evershed)
2. Solar Vortices. Hydrogen Spectroheliogram. (Mount Wilson Observatory)
3. Tracks of Alpha Particles (helium atoms). (C. T. R. Wilson)
4. Tracks of Beta Particles (electrons). (C. T. R. Wilson)
5. Ionization by X-rays. (C. T. R. Wilson)
6. Ions produced by Collision of a Beta particle. (C. T. R. Wilson)
7. The Mass-luminosity Curve.
8. The Ring Nebula in Lyra. Slitless Spectrogram. (W. H. Wright)
9. Flash Spectrum of Chromosphere showing Head of the Balmer Series. (British Eclipse Expedition, 14 Jan. 1926)
10. Solar Prominence. (British Eclipse Expedition, 29 May 1919)
11. Star Cluster ω Centauri. (Cape Observatory)
