PRELIMINARY DISCOURSE. H 



does not contain; they will be treated in the subsequent memoirs 1 

 at greater length, and, if it be in our power, with greater clear 

 ness. The results of our labours concerning the same problems 

 are also indicated in several articles already published. The 

 extract inserted in the Annales de Chimie et de Physique shews 

 the aggregate of our researches (Vol. in. page 350, year 1816). 

 We published in the Annales two separate notes, concerning 

 radiant heat (Vol. iv. page 128, year 1817, and Vol. vi. page 259, 

 year 1817). 



Several other articles of the same collection present the most 

 constant results of theory and observation ; the utility and the 

 extent of thermological knowledge could not be better appreciated 

 than by the celebrated editors of the Annales *. 



In the Bulletin des Sciences (Societe philomatique year 1818, 

 page 1, and year 1820, page 60) will be found an extract from 

 a memoir on the constant or variable temperature of dwellings, 

 and an explanation of the chief consequences of our analysis of 

 the terrestrial temperatures. 



M. Alexandre de Humboldt, whose researches embrace all the 

 great problems of natural philosophy, has considered the obser 

 vations of the temperatures proper to the different climates 

 from a novel and very important point of view (Memoir on Iso 

 thermal lines, Societe d Arcueil, Vol. ill. page 462) ; (Memoir on 

 the inferior limit of perpetual snow, Annales de Chimie et de 

 Physique, Vol. v. page 102, year 1817). 



As to the differential equations of the movement of heat in 

 fluids 3 mention has been made of them in the annual history of 

 the Academy of Sciences. The extract from our memoir shews 

 clearly its object and principle. (Analyse des travaux de VAca 

 demie des Sciences, by M. De Lambre, year 1820.) 



The examination of the repulsive forces produced by heat, 

 which determine the statical properties of gases, does not belong 



1 See note, page 9, and the notes, pages 11 13. 



- Gay-Lussac and Arago. See note, p. 13. 



3 Memoires de VAcademie des Sciences, Tome XII., Paris, 1833, contain on pp. 

 507514, Me moire d analyse sur le mouvement de la chaleur dans les fluides, par M. 

 Fourier. Lu a VAcademie Royale des Sciences, 4 Sep. 1820. It is followed on pp. 

 515 530 by Extrait des notes manuscrites conservees par Vavteur. The memoir 

 is signed Jh. Fourier, Paris, 1 Sep. 1820, but was published after the death of the 

 author. [A. F.] 



