P L A T E S. 



I. Illustrative of Mr. Gilbert Cook's Paper on the Collapse of 

 .Short Tubes by External Pressure. 

 II. Illustrative of Dr. W. Marshall Watts's Paper on the Spectra 

 given by Carbon and some of its Compounds, and, in 

 particular, the " Swan " Spectrum. 

 III. & IV. Illustrative of Messrs. C. E. Magnusson and H. C. Stevens's 

 Paper on Visual Sensations caused bv a Magnetic Field. 

 V. Illustrative of Sir Ernest Rutherford" and Dr. E. N. da C. 

 Andrade's Paper on the Spectrum of the Penetrating y Rays 

 from Radium B and Radium C. 

 VI. Illustrative of Prof. J. C. McLennan's Paper on the 



Absorption Spectrum of Zinc Vapour. 

 VII. Illustrative of Mr. L. Isserlis's Paper on the Application of 

 Solid Hypergeometrical Series to Frequency Distributions 

 in Space. 

 VIII. -XI. Illustrative of Dr. T. Martin Lowry's Paper on an Oxidizable 

 Variety of Nitrogen. 

 XII. Illustrative of Sir Ernest Rutherford and Mr. H. Robinson'e 

 Paper on the Mass and Velocities of the a Particles from 

 Radioactive Substances. 



XIII. Illustrative of Prof. W. M. Thornton's Paper on the Least 



Energy required to start a Gaseous Explosion. 



XIV. Illustrative of Mr. Ivar Maimer's Paper on the High- 



Frequency Spectra of the Elements. 



ERRATA. 



P. 291, line 16, for " (i 1 -i 2 )lh " read " ft-rl)/*, " or " 1— I//,." 



„ lines 19-21, for " the value of I ... . measure of it " read "the 

 value of I will be proportional to 1 - R and I may be taken as 

 an inverse measure of R." 

 „ lines 29, 30, for " The value R'=I/t\ - i 3 will be greater than R," 

 read " The value R' = l - I/fo -i 3 ) will be different from R." 

 P. 382, line 4 from foot of page should read : — 



x y^ki, =Xn-Xoi-Xio+X. 



d*dy 



00 



P. 615. In the denominator of equation (12), for (l-hy -£-£-) read 

 P. 684, line 8, the first integral inside the bracket should be 



£a!& *•*"*£, 



p 4 w 



(1+*V) 



[This is printed correctly in the majority of copies of the November 

 number, but in some of the later "pulls" the :J appears to have been 

 broken off.— W. F.] 



