Copy letter from Robert William Frederick Harrison to Mrs [Hertha] Ayrton 'Dear Mrs Ayrton, I write at once in reply to your letter of Sir Joseph Larmor without writing to send it down to Cambridge, because I am pretty certain that by his letter to you he meant to convey that the illustrations to your paper should consist of two pages of photographs and three pages of diagrams. I think the misunderstanding has arisen through Sir Joseph using the word "illustrations" in the sense of diagrams.' 4 July 1910