IV CONTENTS OF VOL. XXVII. FOURTH SERIES. 



Page 

 Mr. R. Tate on the Liassic Strata of the Neighbourhood of 

 Belfast 74 



Mr. W. R. Swan on the Devonian Rocks of the Bosphorus. 74 



Remarks on the Theory of Gases, by J. Stefan 75 



On Mr. W. Thomson's Method for Measuring Electrical Con- 

 ductivity — Application to Fused Metals, by M. De la Rive. . 77 



NUMBER CLXXX.— FEBRUARY. 



Mr. T. Graham's Speculative Ideas respecting the Constitu- 

 tion of Matter 81 



Mr. J. Gill on the Dynamical Theory of Heat 84 



Dr. W. J. M. Rankine on the Principle of the Equilibrium of 



Polyhedral Frames 92 



Prof. Challis on the Theory of the Velocity of Sound 92 



The Rev. S. Earnshaw's Reply to some Remarks of Dr. Le 



Conte in his paper on the Problem of the Velocity of Sound. 98 

 Prof. Potter's Reply to the Observations of Prof. Le Conte, M.D., 

 respecting the adequacy of Laplace's suggestion for a correc- 

 tion in the Theory of Sound 104 



Dr. Atkinson's Chemical Notices from Foreign Journals .... 107 

 Prof. Odling on the Hexatomicity of Ferricum and Aluminium. 115 



Prof. Odling's Remarks on Chemical Notation 119 



SirW. R. Hamilton on Rober's Construction of the Heptagon. 124 

 Count Paul de Saint-Robert on a Barometrical Formula result- 

 ing from the Observations made by Mr. James Glaisher in 



Eight Balloon-Ascents in 1862 132 



Notices respecting New Books : — Mr. W. Walton on the Ma- 

 thematical and other Writings of Robert Leslie Ellis, M.A. 140 

 Proceedings of the Royal Society : — 



Mr. J. P. Gassiot on Spectrum Analysis, with a Descrip- 

 tion of a large Spectroscope having nine Prisms, and 

 Achromatic Telescopes of two feet focal power ....... 143 



Mr. H. C. Sorby on the Direct Correlation of Mechanical 



and Chemical Forces 145 



Proceedings of the Geological Society : — 



Mr. W. Vicary on the Pebble-bed of Budleigh Salterton. . 154 



The Rev. S. Haughton on the Granites of Ireland 154 



The late Rev. S. Hislop on the further discovery of Fossil 



Teeth and Bones of Reptiles in Central India 155 



Mr. G. S. Poole on the Recent Geological Changes in 



Somerset 155 



Mr. S. V. Wood, Jun„ on the Red Crag in Suffolk and 



Essex 15G 



Some Remarks on the Telescopic Appearance of the Exterior 



Envelope of the Sun, and of its Spots, by theRev.W. R.Dawes. 156 

 On the Rays of the Ultra-violet Solar Spectrum, by M. Mascart. 159 



