444 



INDEX. 



Thomson (J. J.) on a theory of the 

 electric discharge in gases, 427. 



Thompson (Prof. S. P.) on the gra- 

 phic representation of the law of 

 efficiency of an electric motor, 124 ; 

 on polarizing prisms, 435. 



Tides, researches on the, 75. 



Tribe (A.) on dissymmetry in the 

 electric discharge, 391. 



Tuning-forks, method for determin- 

 ing the rate of, 84. 



Tunzelmann (G. W. von) on central 

 forces and the conservation of 

 energy, 152, 299. 



Van der Mensbrugghe (M.) on a 

 theoretic interpretation of the 

 calming eftect of oil on the surges 

 of the sea, 68. 



Vibrations, investigations relating to 

 forced, 73 ; on maintained, 229 ; 

 of a cylindrical vessel containing 

 liquid, on the, 385. 



Vogel (H. W.) on Lockyer's theory 

 of dissociation, 28. 



Walford (E. A.) on the relation of 



the " Northampton Sand " to the 

 Olypeus-grit, 297. 



Warburg (Prof. E.) on effects of re- 

 tentiveness in the magnetization of 

 iron and steel, 246. 



Wead (0. K.) on a simple method 

 of cutting a millimetre-screw, 

 438. 



Wethered (E.) onthe Lower Carboni- 

 ferous rocks in the Forest of Dean, 

 223. 



Wiedemann (Prof. E.) on a modifi- 

 cation in the pycnometer, 369 ; on 

 the condensation of fluids on solid 

 bodies, 440. 



Wilson (A. E.) on the viscosity of a 

 solution of saponine, 406. 



Worthington (A. M.) on the hori- 

 zontal motion of floating bodies 

 under the action of capillary 

 forces, 198. 



Wright (L.) on optical combinations 

 of crystalline films, 301. 



Yung (Dr. E.) on the errors of our 

 sensations, 259. 



END OF THE FIFTEENTH VOLUME. 



FLAMMAM. 



Printed by Taylor and Fkakcis, Eed Lion Court, Fleet Street. 



