VI CONTENTS OF VOL. XV. FIFTH SERIES. 



N TJMBEE XCV.— MAT. 



Page 

 Mr. L. "Wright on Optical Combinations of Crystalline Films. 



(Plate VI.) 301 



Mr. R. H. M. Bosanquet on Permanent Magnetism 309 



Mr. S. Bidwell on a Method of Measuring Electrical Resist- 



ances with a Constant Current 316 



Mr. J. Rand Capron on the Auroral Beam of November 17, 



1882. (Plate VII.) 318 



Mr. W. J. Nicol on a new Porm of Constant-Temperature 



Bath 339 



Mr. E. H. Hall on " Rotational Coefficients " of various Metals 341 

 Professors Ayrton and Perry on the Resistance of the Electric 



Arc 346 



Mr. R. T. Glazebrook on Polarizing Prisms 352 



Notices respecting New Books : — 



Mr. R. T. Glazebrook's Physical Optics 362 



Mr. L. Clark's Transit Tables for 1883 for Popular Use . . 363 

 Proceedings of the Geological Society : — 



Mr. T. Gray on Gray and Milne's Seismographic Appa- 

 ratus 363 



Dr. A. Geikie on the supposed Pre-Cambrian Rocks of 



St. David's 365 



On the Use of the Term " Force," by Walter R. Browne . . 368 

 On a Modification in the Pycnometer, by Prof. E. Wiedemann 369 

 On the Upper Limit of the Perceptibility of Sounds, by E. 

 Pauchon 371 



NUMBER XCVL— JUNE. 



Mr. H. R. Droop on Colour-Sensation 373 



Lord Ray lei gh on the Vibrations of a Cylindrical Vessel con- 

 taining Liquid 385 



Mr. W. Moon on a Method of Calculating the Amount of 

 Magnetism of a Magnetic Circle for each Strength of Cur- 

 rent acting on it 389 



Mr. A. Tribe on Dissymmetry in the Electrolytic Discharge . . 391 

 Professors Avrton and Perry on winding Electromagnets. 



(Plates Vlil. & IX.) 397 



Mr. E. H. Cook on the Regenerative Theory of Solar Action 400 

 Messrs. W. H. Stables and A. E. Wilson on the Viscosity of a 



Solution of Saponine 406 



Mr. R. T. Glazebrook on Curved Diffraction-gratings 414 



Sir John Conroy on a new Photometer 423 



Mr. J. J. Thomson on a Theory of the Electric Discharge in 



Gases 427 



Mr. E. J. Smith on a new Eorm of Horse-power Indicator . . 434 



