434 Mr. 0. Heaviside on Electromagnetic Waves, and the 



Naphthaquinone : — 



CHCO 



HC ' C CH 



IN /I I 

 HO , C OH 



CHCO 



Fig. 13. 



The oxidation not further affecting the second ring 



Tetrahydronaphthalene : — 



CH CH 2 



HC C CH 2 



|\ /\ I 



HC C CH 2 



CH CH 2 



Fig. 14 





The addition not going further than to the extent of 

 4 univalent atoms. 



I have adopted in this paper a method of treatment of the 

 carhon atom in space somewhat different from the original 

 conception of it as an atom situated at the centre and having 

 its affinities directed towards the angles of a regular tetrahe- 

 dron, in that I have treated it as itself representable by a 

 regular tetrahedron having its four affinities acting at the 

 angles. It is, I think, a natural and perfectly legitimate 

 method of treatment, and is in full accordance with Wis- 

 licenus' conception, when he states (Ber. xxi. p. 584), " Ich 

 halte es nicht fur unmoglich dass das Kohlenstoffatom ein 

 Gebilde sei welche in seiner Gestalt einem regularen Tetraeder 

 mehr oder weniger vielleicht recht sehr ahnelt." 



XL VIII. On Electromagnetic Waves, especially in relation to the 

 Vorticity of the Impressed Forces ; and the Forced. Vibrations 

 oj Electromagnetic /Systems. By Oliver Heaviside. 



[Continued from p. 382.] 



Cylindrical Electromagnetic Waves. 

 49. TN concluding this paper I propose to give some cases of 

 JL cylindrical waves. They are selected with a view to 

 the avoidance of mere mathematical developments and unin- 



