Draft letter, from Sir John Herschel to William Lassell, dated at Collingwood Draft letter in Herschel's hand with extensive revisions. Is dismayed to find in the new edition of his own Outlines Astr. that he has attributed the discovery of Hyperion to W. R. Dawes without crediting William Lassell; will have this corrected in a future edition. Annotation in red pencil "original seen" by the copyist of the letter in 1873-4, as part of the correspondence project led by Colonel John Herschel FRS following the death of his father. 15 September 1858