Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Prof. [Frank] Horton, FRS Give thanks for Prof. [Frank] Horton accepting to serve on the Committee for Physics. Explains that his paper on 'Soft X-Rays' [ Full title 'Critical potentials for soft X-ray excitation'] is still with a referee who has had it for a long time. 23 December 1927