EXED . 



in 



THE 



LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIE& 



[SIXTH SEME 



JUS E 1907, 



LIX. On the Radiation from Moving Systems of 



and on the Spectrum of Canal Rays. By G. A. Schott, 

 B.A., B.Sc, University College of Wales, Aberystwyth *, 



§ 1. TN a previous communication t I nave examined that 

 X radiation from a stationary ring of electrons, which 

 are in orbital motion in a suitable controlling field, and also 

 from a system composed of a large number of similar inde- 

 pendent rings. A ring of n electrons emits 6n waves of 

 frequencies of the same order as those of spectrum lines ; 

 but of these waves at most 18 are of sufficient intensity, 

 under ordinary conditions, to produce observable lines. Thus 

 we cannot, by means of a single ring, account for a complete 

 spectrum series or band ; but we may be able to do so by 

 means of a system of rings coupled together by their mutual 

 actions. For this purpose the study of the single ring is 

 necessary. 



§ 2. In a series of important experiments J. Stark 1 has 

 shown that the canal-ray spectrum contains series lines, each 

 line being split up into a narrow undisplaced line, due to nearly 

 stationary ions, and a broad displaced line due to ions moving 

 with velocities ranging from 10" to 5.10 7 cm./sec. The latter 

 is separated by a dark space from the former, and has a 



* Communicated by the Author, 

 t Schott, Phil. Mag. [6] vol. xiii. p. 189. 



X J. Stark, ' Nature,' vol. lxxiii. pp. 78, 389, 533 ; Ann. der Physik, 

 vol. cccxxvi. p. 401. 



Phil. Mag. S. 6. Yob 13. Xo. 78. June 1907, 2 Y 



