PRELIMINARY DISCOURSE. 13 



will direct all these measures, and assign their precision. No 

 considerable progress can hereafter be made which is not founded 

 on experiments such as these ; for mathematical analysis can 

 deduce from general and simple phenomena the expression of the 

 laws of nature ; but the special application of these laws to very 

 complex effects demands a long series of exact observations. 



The complete list of the Articles on Heat, published by M. Fourier, in the 

 Annales de Chimie et de Physique, Series 2, is as follows : 



1816. III. pp. 350375. Theorie de la Chaleur (Extrait). Description by the 

 author of the 4to volume afterwards published in 1822 without the chapters on 

 radiant heat, solar heat as it affects the earth, the comparison of analysis with 

 experiment, and the history of the rise and progress of the theory of heat. 



1817. IV. pp. 128 145. Note sur la Chaleur rayonnante. Mathematical 

 sketch on the sine law of emission of heat from a surface. Proves the author s 

 paradox on the hypothesis of equal intensity of emission in all directions. 



1817. VI. pp. 259 303. Questions sur la theorie physique de la chaleur 

 rayonnante. An elegant physical treatise on the discoveries of Newton, Pictet, 

 Wells, TVollaston, Leslie and Prevost. 



1820. XIII. pp. 418 438. Sur le refroidissement seculaire de la terre (Extrait). 

 Sketch of a memoir, mathematical and descriptive, on the waste of the earth s 

 initial heat. 



1824. XXYII. pp. 136 167. Eemarques generates sur Ics temperatures du globe 

 terrestre et des espaces planetaires. This is the descriptive memoir referred to 

 above, Mem. Acad. d. Sc. Tome VII. 



1824. XXYII. pp. 236 281. Eesume theorique des proprietes de la chaleur 

 rayonnante. Elementary analytical account of surface-emission and absorption 

 based on the principle of equilibrium of temperature. 



1825. XXYIII. pp. 337 365. Eemarques sur la theorie mathematique de la 

 chaleur rayonnante. Elementary analysis of emission, absorption and reflection 

 by walls of enclosure uniformly heated. At p. 364, M. Fourier promises a Theorie 

 physique de la clialeur to contain the applications of the Theorie Analytique 

 omitted from the work published in 1822. 



1828. XXXYII. pp. 291 315. Eecherches experimentales sur la faculte con- 

 ductrice des corps minces soumis a Vaction de la chaleur, et description d un nouveau 

 thermometre de contact. A thermoscope of contact intended for lecture demonstra 

 tions is also described. M. Ernile Yerdet in his Conferences de Physique, Paris, 

 1872. Part I. p. 22, has stated the practical reasons against relying on the 

 theoretical indications of the thermometer of contact. [A. F.] 



Of the three notices of memoirs by M. Fourier, contained in the Bulletin des 

 Sciences par la Societe Philomatique, and quoted here at pages 9 and 11, the first 

 was written by M. Poisson, the mathematical editor of the Bulletin, the other two by 

 M. Fourier. [A. F.] 



