PLATES. 



I. Illustrative of Prof. L. T. JNlore's Paper on Electrostriction. 

 II. Illustrative of Dr. J. A. Ilarker's Paper on a Direct-reading 

 Potentiometer. 



III. Illustrative of Mr. A. Whitwell's Paper on Eefraction at a 



Cylindrical Surface. 



IV. Illustrative of Prof. J. Trowbridge's Paper on Spectra of Gases 



and Metals at High Temperatures. 

 V. Illustrative of Mr. Richardson's Paper on the Positive Ionization 

 produced by Hot Platinum in Air at Low Pressures. 

 VI.- VIII. Illustrative of Prof. R. W. Wood's Paper on the Anomalous 

 Dispersion, Absorption, and Surface-Colour of Nitroso- 

 dimethyl-aniline. 

 IX. & X. Illustrative of Mr. W. B. Cartmel's Paper on the Anomalous 

 Dispersion and Selective Absorption of Fuchsin. 

 XI. Illustrative of Mr. G. Owen's Paper on the Condensation Nuclei 

 produced in Air and Hydrogen by Heating a Platinum Wire. 

 XII. Illustrative of Dr. S. R. Milner's Paper on an Automatic Mercury 

 Vacuum-pump. 

 XIII. & XIV. Illustrative of Prof. R. W. Wood and Mr. J. H. Moore's 

 Paper on the Fluorescence and Absorption Spectra of Sodium 

 Vapour. 

 XV. Illustrative of Messrs. K. Honda and S. Shimizu's Paper on 

 Change of Length of Ferromagnetic Substances by Mag- 

 netization. 

 XVI. Illustrative of Dr. C. C. Farr's Paper on the Interpretation of 

 Milne Seismograms. 

 XVII. Illustrative of Dr. J. E. Ives's Paper on the Law of the 

 Condenser in the Induction -Coil. 

 XVIII. Illustrative of Mr. S. R, Cook's Paper on the Distribution of 

 Pressure around Spheres in a V^iscous Fluid. 

 XIX. Illustrative of Mr. G. W. Walker's Paper on the Theory of 

 Refraction in Gases. 

 XX. Illustrative of Sir W. Ramsay and Dr. B. D. Steele's Paper on 

 the Vapour-Densities of some Carbon Compounds. 

 XXI. Illustrative of Mr. T. H. Blakesley's Paper on Single-Piece 

 T pusps 

 XXII. & XXIII. Iliustrative of Prof. T. R. Lyle's Paper on a Wave- 

 Tracer and Analvser. 

 XXIV. Illustrative of Mr. H. S. Allen's Paper on the Effect of Errors 

 in Ruling on the Appearance of a Diffraction-Grating. 

 XXV. Illustrative of Messrs. J. E. Petavel and R. S. Hutton's Paper 

 on the Effect of Pressure upon Arc Spectra. 

 XXVI. Illustrative of Prof. R. W. Wood's Paper on Photographic 



Reversals in Spectrum Photographs. 

 XXVII. Illustrative of Mr. W. E. Williams's Paper' on the Influence of 

 Stress and of Temperature on the Magnetic Change of 

 Resistance in Iron, Nickel, and Nickel-Steel. 



ERRATA. 



For y in pages 20, 23, 24, 25, 26, read f. 



Page 24, bottom line, for /= ~ ^ ^ read /= ;^- 



"^ ' l-s/k l + s/k' 



