PLATES. 



I. Illustrative of Mr. V. Lough's Paper on the Beating- Tories of 



Overblown Organ Pipes. 

 II. Illustrative of Messrs. A. F. Joffe and M. V. Kirpitcheva's 

 Paper on Rontgenogranis of Strained Crystals. 

 III.-V. Illustrative of Mr. G. A. Hemsalech and the Comte de 

 Gramont's Paper on the Occurrence of Spark Lines (En- 

 hanced Lines) in the Arc. 

 VI.&VII. Illustrative of Prof. C. V. Raman and Mr. Nihal Karan Sethi's 

 Paper on the Convection of Light (Fizeau Effect) in Moving 

 Gases. 

 VIII. Illustrative of Mr. H. P. Waran's Paper on an Interferometer 

 Method of determining the Phase Difference resulting from 

 Metallic Reflexion. 

 IX. Illustrative of Mr. B. N. Chuckerbutti's Paper on the Defor- 

 mation of the " Rings and Brushes," as observed thiough a 

 Spath Hemitrope. 

 X. & XL Illustrative of Prof. A. L. Narayan's Paper on Coupled Vibra- 

 tions by means of a Double Pendulum. 

 XII. Illustrative of Prof. A. L. Narayan's Paper on Mechanical 

 Illustration of three Magnetically Coupled Oscillating Cir- 

 cuits. 



XIII. Illustrative of Drs. Paul D. Foote, F. L. Mohler, and W. F. 



Meggers's Paper on a Significant Exception to the Principle 

 of Selection. 



XIV. Illustrative of Prof. A.- L. Narayan's Paper on a Modified 



Form of Double Slit Spectrophotometer. 

 XV. Illustrative of Messrs. A. L. Narayan and G. Subrahmanyam's 

 Paper on Surface Tension of Soap Solutions for Different 

 Concentrations. 

 XVI. Illustrative of Prof. R. W. Wood's Paper on Fluorescence 

 and Photo-Chemistry. 

 XVII .-XXI. Illustrative of Mr. G. A. Hemsalech and the Comte de 

 Gramont's Paper on the Occurrence of Spark Lines (En- 

 hanced Lines) in the Arc. 

 XXII. Illustrative of Mr. H. Carrington's Paper on Young's Modulus 

 and Poisson's Ratio for Spruce. 



XXIII. Illustrative of Mr. D. Coster's Paper on the Spectra of X-rays 



and the Theory of Atomic Structure. 



XXIV. Illustrative of Prof. R. Whiddington's Paper on X-ray 



Electrons. 



