CONTENTS of N° 279.— Fourth Series. 



XX. On the Reduction of the Second Axiom of the Mechanical 

 Theory of Heat to general Mechanical Principles. By R. Clausius. page 161 



XXI. Description of a Model of a Conoidal Cubic Surface called 

 the " Cylindroid," which is presented in the Theory of the Geometrical 

 freedom of a Rigid Body. By Robert Stawell Ball, A.M., Pro- 

 fessor of Applied Mathematics and Mechanism, Royal College of 

 Science for Ireland 181 



XXII. On the steady Flow of a Liquid. By Henry Moseley, M. A., 

 D.C.L., Canon of Bristol, F.R.S., Corresponding Member of the In- 

 stitute of France, &c 184 



XXIII. On a supposed new Integration of Differential Equations of 

 the Second Order. By Professor Cayley, F.R.S 197 



XXIV. On the General Circulation and Distribution of the Atmo- 

 sphere. By Professor J. D. Everett, of Queen's College, Belfast . . 199 



XXV. Account of Experiments upon the Resistance of Air to the 

 Motion of Vortex-rings. By Robert Stawell Ball, A.M., Professor 

 of Applied Mathematics and Mechanism, Royal College of Science for 

 Ireland, Dublin 20S 



XXVI. On the Action of Magnetism on Gases traversed by Elec- 

 tric Discharges. By MM. A. de la Rive and E. Sarasin 211 



XXVII. Proceedings of Learned Societies : — 

 Royal Society : — Dr. W. Huggins on the Spectrum of Uranus 



and the Spectrum of Comet I., 1871 ; Dr. J. H. Gladstone 



and Alfred Tribe on a Law in Chemical Dynamics .... 223-226 



Geological Society 228-232 



XXVIII. Intelligence and Miscellaneous Articles: — 

 On the Velocity of Propagation of Electrodynamic Effects, by 



Dr. Helmholtz 23a 



On a Native Sulphide of Antimony from New Zealand, by M. M. 



Pattison Muir, F.C.S., Student in the Laboratory of the An- 



dersonian University, Glasgow 23( 



On the Reversal of the Lines of the Spectra of Metallic Vapours, 



by M. A. Cornu 237 



%* It is requested that all Communications for this Work may be addressed, 

 post-paid, to the Care of Messrs. Taylor and Francis, Printing Office, Rec 

 Lion Court, Fleet Street, London. 



