This series of book lists and catalogues relates to the administration of the library at Hardwick and Chatsworth. The books represented in these catalogues and lists were managed and in some cases acquired by Hobbes, Whildon and other upper servants of the Cavendish household. Some of the items in this series are posthumous to Hobbes but relate to earlier book lists in the series and in this way to Hobbes.
Hobbes was responsible for the earliest existing catalogue of the library - compiled in the 1620s (HS/E/1A ) and the catalogue that follows in this series was created by James Whildon in 1657 (HS/ADD/1) and is based on Hobbes's catalogue, dividing theological and religious books from other secular works. Whildon also produced a listing of the Hardwick books according to the shelves on which the books were kept (see HS/ADD/3 and HS/ADD/4).
The other two catalogues in this series are dated later and are in a different hand - possibly that of another librarian, who was responsible for the books kept in the Chatsworth library after the completion of the building work at Chatsworth commissioned by William Cavendish (4th Earl and later 1st Duke of Devonshire) in the 1690s. Unlike the earlier catalogue, HS/ADD/2 specifies a collection of manuscripts in the Chatworth library, which includes some works by Hobbes.
Possibly some items from the series HS/A were added to the Hobbes collection from the library, as some works by Hobbes appear in the later 17th-century library catalogues in this series.