Some of Henry Cavendish's earliest work, possibly influenced by his father Lord Charles' interets, lay in thermometry (the measure of heat) and calorimetry (measuring the amount of thermal energy transferred in a chemical or physical process). He may have commenced this work shortly after leaving Cambridge in 1753. Thorpe suggests that Cavendish made several discoveries independent of Joseph Black (1728-1799, physicist and chemist who is known for his research into the nature of heat) (Thorpe, Sir Edward, "The Scientific Papers of Henry Cavendish: Chemical and Dynamical" (1921; Cambridge, Cambridge University Press), Vol II, p327). His research focused on the measurement of temperature but also evolved into a wider, general theory of heat. In July 1969, the great-great-grandson of Charles, 1st Baron Chesham, John Charles Compton Cavendish, auctioned some material that he had inherited relating to Henry Cavendish. These items included a paper on heat, now with the Public Archives of Canada, that is "the only developed mechanical theory of heat from the eighteenth century" (McCormmach, Russell, "Speculative Truth: Henry Cavendish, Natural Philosophy and the Rise of Modern Theoretical Science" (2004; Oxford, Oxford University Press), pvii).
HY/3/1-15 were catalogued prior to 2024. In 2024, HY/2/13-23 were arranged and catalogued from various folders to this grouping on the basis of subject matter (see Arrangement field).
Some of the records have been published, primarily in Thorpe 1921, Vol II pp326-398. In that publication, the following appear:
HY/3/19 pp327-51
HY/3/5/2 pp351-4
HY/3/5/1 pp354-62
HY/4/21 p364
HY/3/1 pp362-80
HY/3/4/3 pp381-4
HY/3/8 p384
HY/3/18 p389
HY/3/3 pp390-1
HY/4/24 pp391-2
HY/4/10 pp394-5