Copy letter from Lord Rayleigh [John William Strutt], to Dr Macdonald, Fellow of the Royal Society 'Dear Dr Macdonald, I have read your paper herewith returned. For myself I cannot see that the analogy will work. The idea is a very old one having been suggested by Newton. I am, yours truly, (signed) Rayleigh Sec. R.S. [Secretary, Royal Society]'. 30 November 1895