Copy letter from an unknown correspondent, to Harrisons & Son The correspondent asks the Messrs to make electros of the figures illustrating Mr Lockyer's paper from 'Proceedings [of the Royal Society]' number 166, pp six, 24 and 82, and send them with a bill to the Secretary of the Society for the Promotion of Christian Knowledge. They are for publication in a book by Professor A H Green. 28 May 1890