Copy letter, from Sir John Herschel to Rudolf Wolf, dated at Collingwood Copy of a letter. Has sent Rudolf Wolf a copy of John Frederick William Herschel's catalog of nebulae and also a biographical sketch of John Frederick William Herschel's father. Thanks Rudolf Wolf for and praises Rudolf Wolf's works on sun spots and on the aurora borealis. Notes that G. B. Airy is now disposed to accepting the existence of solar 'willow leaves.' 5 May 1865