Copy letter from Robert William Frederick Harrison, to Messrs Harrison & Sons, St Martin's Lane, W.C. 'Please prepare electros of the blocks illustrating Prof. J. [Professor John] Milne's Bakerian Lecture on "Recent Advances in Seismology" & send them, with your account, to the Editor of "Nature" c/o [care of] Messrs Macmillan & Co Ltd, St Martin's Street, London, W.C.'. 1 May 1906