Letter from Thomas Gold to Dr Melvin Calvin, Director, Laboratory of Chemical Biodynamics, University of California, Berkeley, California Encloses some pages form a proposal concerning the relation between the supply of surface carbon and the evolution of atmospheric oxygen. Gold would be very interested in his comments and those of his colleagues. Gold is making some headway and has a number of converts in Washington and elsewhere. Would like to plan another trip to the West Coast in June or so. Asks when Calvin and his colleagues would be there. 3 May 1978