1930 January 29 meeting of the British Astronomical Association

1930 January 31 geophysical discussion

1930 June 13 meeting of the Royal Astronomical Society

1930 June 13 meeting of the Royal Astronomical Society (cont.)

1930 June 18 meeting of the Royal Meteorological Society

1930 June 25 meeting of the British Astronomical Association

1930 Lucifer CCD Spectrum

1930 March 14 meeting of the Royal Astronomical Society

1930 March 19 meeting of the Royal Meteorological Society

1930 March 26 meeting of the British Astronomical Association

1930 March 7 geophysical discussion

1930 May 2 geophysical discussion

1930 May 21 meeting of the Royal Meteorological Society

1930 May 28 meeting of the British Astronomical Association

1930 May 9 meeting of the Royal Astronomical Society

1930 November 14 meeting of the Royal Astronomical Society

1930 November 19 meeting of the Royal Meteorological Society

1930 November 26 meeting of the British Astronomical Association

1930 November 7 geophysical discussion

1930 October 29 meeting of the British Astronomical Association