Copy letter from Herbert Rix, to Messrs Taylor & Francis, Red Lion Court, Fleet Street, E.C. 'Lord Kelvin send us four diagrams which he says are to appear in the April number of the "Philosophical Magazine" in illustration of a paper by Dr Kerr. The number of the article is XXXIV. Could you kindly let me have at our expense cliches of these four figures? delivering them here by Monday if possible. HR'. 9 March 1894