Correspondence and papers regarding eclipse expeditions to observe the annual eclipse of September 1951 and the solar eclipse of February 1952, including the following items:

Letter from D.H. Sadler enclosing solar eclipse data for 1950-1954.

Letter from D.C. Martin, Royal Society, concerning the expedition to Rio de Oro, 1951.

R. Atkinson's correspondence with D.H. Menzel, Harvard College Observatory, regarding weather data in Africa along the eclipse track.

Copies of letters from G.W. Robinson, University College of North Wales, Bangor, to F.J.M. Stratton, Cambridge, referring to the Ebro Observatory, Spain, and its interest in the 1951 expedition.

Letter from the Spanish Tourist Office giving travel information regarding Rio de Oro.

Letter from H. Spencer Jones on finance.

Letters from D. Perfect and H.M. Smith, Abinger, with Smith's notes on radio time signals and equipment for the 1952 expedition.

Letters from G.T. Thairi, Royal Air Force Flying College, Manby, Lincolnshire.

R. Atkinson's manuscript notes on weather conditions at various locations and calculations for 1951 and 1952.

I.A.U. report on 'Weather Conditions for the Eclipse of February 25, 1952'.

Report by G. Van Biesbroeck, Yerkes Observatory, on sites for the eclipse.

Miscellaneous data, including manuscript notes on the time of mid-eclipse, Kuwait, and on the determination of azimuth.