CONTENTS of N c 307.— Fourth Series. 



XLII. On the Action of a Blast of Sand in cutting hard Material. 



By Professor Osborne Reynolds, M.A page 337 



XLHL On the Temperature and Physical Constitution of the Sun. 



(Second Memoir.) By P. Zollner 343 



XLIY. On the Vibrations of Approximately Simple Systems. 



By Lord Rayleigh, P.B.S 357 



XLY. On the Determination of the Specific Heat of Gases and 



Vapours at Constant Volumes. By K. C. Nichols 361 



XLVI. On some Results of the Earth's Contraction from Cooling, 

 including a discussion of the Origin of Mountains. By James D. 

 Dana. — Part V. Formation of the Continental Plateaux and Oceanic 



Depressions 363 



XL VII. On the " Black Drop " in the Transit of Venus. By T. 



K. Abbott, M.A., Fellow of Trinity College, Dublin 375 



XL VIII. On the Motions of Camphor and of certain Liquids on 



the Surface of Water. By Charles Tomlinson, F.B.S 376 



XLIX. On Integrating Differential Equations by Factors and Dif- 

 ferentiation, with Applications in the Calculus of Variations. By 



Professor Challis, M.A., F.R.S., F.R.A.S 38S 



L. On Statical and Dynamical Ideas in Chemistry. — Part IV. 

 (conclusion). On the Idea of Motion. By Edmund J. Mills, D.Sc. 398 



LI. Notices respecting New Books : — An Elementary Treatise on 

 the Differential Calculus, containing the Theory of Plane Curves, with 

 numerous Examples. By Benjamin Williamson, A.M., Fellow and 



Tutor, Trinity College, Dublin 406 



LIT. Proceedings of Learned Societies : — 



Royal Society : — Messrs. C. H. Stearn and Gr. H. Lee on the 

 Effect of Pressure on the Character of the Spectra of Gases ; 

 Mr. J. N. Lockyer's Researches in Spectrum-Analysis in 



connexion with the Spectrum of the Sun. — No. II 406-410 



LIII. Intelligence and Miscellaneous Articles : — 



On the Condensation of Oases and Liquids by Wood-charcoal. 

 Thermic Phenomena produced on the Contact of Liquids and 

 Charcoal. Liquefaction of the Condensed Oases, by M. Mel- 

 sens 410 



On the possible Existence of a Lunar Atmosphere, by E. 



Neison, E^q 411 



A Contribution to the History of the Horizontal Pendulum, by 

 Professor Safarik 412 



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

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

 Lion Court, Fleet Street, London. 





