Copy of draft letter, from Sir John Herschel to Dionysius Lardner, dated at Slough Copy of draft letter, copied as part of the correspondence project led by Colonel John Herschel FRS following the death of his father. Has some difficulty in producing his article on Light for the Cabinet Cyclopaedia as the publishers of the Encyclopaedia Metropolitana consider it would be harmful to their own publication. 16 February 1829