Copy letter from Herbert Rix, to Professor William Edward Ayrton, [Fellow of the Royal Society] 'Dear Prof Ayrton, Collings says that the illusts [illustrations] on pp.4 & 5 of the enclosed proof on zinco graphs from the drawings themselves. The pencilled criticisms indicate defects which will all disappear when the cuts are "brought up" for printing off. He says that they will look just brought to the level of the type & get properly supplied with ink. This is always done before printing off. Yours truly Herbert Rix Asst Sec RS [Assistant Secretary, Royal Society]'. 8 October 1891