Letter from J D Griffith Davies, Assistant Secretary of the Royal Society, on a paper 'Short period fluctuations in the characteristics of wireless echoes from the ionosphere' by Thomas Lydwell Eckersley and F T Farmer to H Wooldridge, on behalf of the Department of Scientific and Industrial Research Papers are printed at the Royal Society's expense, solely for government departments, at a considerable loss. The only copies that will be printed are those ordered by the government departments. Thanks him for providing a list of departments who might be interested in the paper. Apologises for not making clear the the papers are confidential. [Published in Proceedings of the Royal Society A, 1945]. 29 January 1941