Copy letter, from Sir John Herschel to Richard Hodgson, dated at Collingwood Copy of letter, copied as part of the correspondence project led by Colonel John Herschel FRS following the death of his father. Did not insinuate that Richard Hodgson plagiarized John Frederick William Herschel's idea of 'diagonal reflector,' but feels justified in defending John Frederick William Herschel's claim to being first to apply it. 27 February 1864