CONTENTS OF VOL. XXIII. FIFTH SERIES. V 



Page 



Sir W. Thomson on the Waves produced by a Single Impulse 

 in Water of any Depth, or in a Dispersive Medium 252 



Sir W. Thomson on the Formation of Coreless Vortices by 

 the Motion of a Solid through an Inviscid Incompressible 

 Fluid 255 



Prof. H. A. Eowland on the Eelative Wave-lengths of the Lines 

 of the Solar Spectrum 257 



Mr. L. Bell on the Absolute Wave-length of Light 265 



Prof. W. C. Unwin on Measuring-Instruments used in 

 Mechanical Testing 282 



Sir W. Thomson on the Equilibrium of a Gas under its own 

 Gravitation only 287 



Mr. AV. Brown's Preliminary Experiments on the Effects of 

 Percussion in Changing the Magnetic Moments of Steel 

 Magnets 293 



Notices respecting New Books : — 



Annual Companion to the ' Observatory,' a Monthly 



Beview of Astronomy 299 



Mr. G. S. Carr's Synopsis of Elementary Eesults in Pure 

 Mathematics . / 300 



On the Action of the Discharge of Electricity of High Poten- 

 tial on Solid Particles suspended in the Air, by A. von 

 Obermayer and M. von Pichler 301 



On a Simple and Convenient form of Water-Battery, by 

 Henry A. Eowland 303 



On the Galvanic Polarization of Aluminium, by Dr. F. Streinz. 304 



NUMBEE CXLIIL— APEIL. 



Prof. Ludwig Boltzmann on the Assumptions necessary for 

 the Theoretical Proof of Avogadro's Law 305 



Prof. S. P. Thompson on an Arc-Lamp suitable to be used with 

 the Duboscq Lantern. (Plate III.) 333 



Mr. E. H. M. Bosanquet on Electromagnets. — VII. The Law 

 of the Electromagnet and the Law of the Dynamo 338 



Messrs. E. Gibson and E. A. Gregory on the Tenacity of 

 Spun Glass 351 



Mr. T. Gray on an Improved Eorm of Seismograph. (Plate 

 IV.) 353 



Mr. E. Y. Edgeworth on Discordant Observations 364 



Dr. E. J. Mills on the Action of Heat on Potassic Chlorate 

 and Perchlorate 375 



Prof. J. J. Thomsons Eeply to Prof. Wilhelm Ostwald's criti- 

 cism on his paper " On the Chemical Combination of Gases " 379 



On certain Modifications of a Eorm of Spherical Integrator, 

 by Y. Ventosa 381 



