VI CONTENTS OF VOL. XXXIV. — FOURTH SERIES. 



Page 



On Brewster's Neutral Point, by Pliny Earle Chase 325 



Note on the Force which the Muscle of a Frog can develope in 



contracting, by M. J. Rosenthal 325 



On the Absorption of Obscure Heat, by M. P. Desains 327 



On the Change of Obliquity as a cause of Change of Climate, by 



J. Carrick Moore 328 



NUMBER CCXXXL— NOVEMBER. 



Mr. D. Forbes's Researches in British Mineralogy 329 



Mr. G. W. Keely on a new Attempt to determine the Resultant 



of two Pressures on a Fixed Point 354 



Mr. H. C. Sorby on the Colour of the Clouds and Sky 356 



Mr. J. K. Laughton's Inquiry into the Evidence on which the 



Theory of the Circulation of the Atmosphere is based 359 



Dr. Rankine on Isoperimetric Regular Polygons . . 365 



M. B. Riemann's Contribution to Electrodynamics 368 



Dr. A. Naumann on the Velocity of Atomic Motion 373 



Mr. F. A. Tarleton on the Figure of the Bullet which experi- 

 ences the least resistance from the Air 377 



Dr. Rankine on the Approximate Rectification of Circular Arcs. 381 

 Dr. Gerlach's Contribution to the Mechanical Theory of the 



Electrical Current 382 



Proceedings of the Royal Society : — 



Sir W. Thomson on a Self-acting Apparatus for multiplying 



and maintaining Electric Charges 391 



Proceedings of the Geological Society : — 



Mr. H. B. Medlicott on the Alps and the Himalayas , . . . 396 

 Mr. D. Mackintosh on the Terminal Curvature of Slaty 



Laminae in West Somerset 397 



Messrs. P. M. Duncan and J. Thomson on Cyclocyathus. . 398 



Dr. Dawson on a new Pulmonate Mollusk 398 



Mr. J. W. Salter on some tracks of JPteraspis (?) 398 



Mr. J. W. Salter on a new IAngulella 399 



Mr. G. Busk on the Dentition of Fossil Bears 399 



Dr. J. Haaston the Geology of the Province of Canterbury, 



New Zealand 399 



The Rev. J. H. Timins on the Chemical Geology of the 



Malvern Hills 400 



Mr. T. M. Hall Townshend on the Relative Distribution 



of Fossils throughout the North Devon series 400 



Mr. W. R. Swan on the Geology of the Princes Islands . . 401 

 Mr. C. Collingwood on the Sulphur Springs of Northern 



Formosa 401 



Mr. G. B. Stacey on the Geology of Benghazi 401 



Mr. E. Thornton on the Existence of large Coal-fields in 

 the Province of St. Catherine's, Brazil 402 



