Letters mostly to Clark, with some to his wife Frances Clark (d.1908), Adam Sedgwick (1785-1873) and others, mainly routine in nature, and collected for their autograph value. Another volume, containing letters of scientists, was not acquired. The original numbering in each volume has been retained; in this catalogue the letters are grouped by subject.

Arranged, bound and listed by Munby, containing letters by collectors of books and manuscripts. The letters are arranged in order of the author's date of birth. There is also an alphabetical index.

16 letters to Kay-Shuttleworth, mostly concerning arrangements for meetings and acceptances of dinner invitations; 6 letters to other members of the family from various correspondents, 1842-1860; 6 miscellaneous letters.