THE 

 LONDON, EDINBURGH and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



SUPPLEMENT to VOL. II. FOURTH SERIES. 



LXXVI. On the Centrifugal Theory of Elasticity, as applied to 

 Gases and Vapours. By William John Macquorn Ran- 

 KiNE, C.E., F.R.S.E., F.R.S.S.A. ^c* 



(1.) npHE following paper is an attempt to show how the 

 -»- laws of the pressure and expansion of gaseous sub- 

 stances may be deduced from that which may be called the 

 hypothesis of molecular vortices, being a peculiar mode of con- 

 ceiving that theory which ascribes the elasticity connected with 

 heat to the centrifugal force of small revolutions of the particles 

 of bodies. 



The fundamental equations of this theory were obtained in the 

 year 1842. After having been laid aside for nearly seven years, 

 from the want of experimental data, its investigation was resumed 

 in consequence of the publication of the experiments of M. Reg- 

 nault on gases and vapours. Its results having been explained 

 to the Royal Society of Edinburgh in February 1850, a sum- 

 mary of them was printed as an introduction to a paper on the 

 Mechanical Action of Heat in the twentieth volume of the 

 Transactions of that body. I now publish the investigation in 

 detail in its original form, with the exception of some interme- 

 diate steps of the analysis in the second and third sections, 

 which have been modiiied in order to meet the objections of 

 Professor William Thomson of Glasgow, to whom the paper was 

 submitted after it had been read, and to whom I feel much in- 

 debted for his friendly criticism. 



This paper treats exclusively of the relations between the den- 

 sity, heat, temperature, and pressure of gaseous bodies in a sta- 

 tical condition, or when those quantities are constant. The 

 laws of their variation belong to the theory of the mechanical 

 action of heat, and are investigated in the other paper already 

 referred to. 



The present paper consists of six sections. 



The first section explains the hypothesis. 



* Communicated by the Author, having been read to the Royal Society 

 of Edinburgh, February 4, 1 850. 



Phil. Mag. S. 4. No. 14. Suppl. Vol. 2. 2 M 



