26th January, igog. 



Mr. Wm, Svvanston, F.G.S., in the Chair. 



"THE PRODUCTION AND DETECTION OF 

 ELECTRIC WAVES." 



By Mr. John M. Finnegan, B.A., B.Sc. 



(Abstract.) 



Mr. Finnegan, at the outset, said he assumed the existence 

 of ether, a non-atomic, absolutely continuous medium, without 

 breaks or gaps of any kind, permeating space, the atom super- 

 imposed on it, not substituted for it, but probably a definite 

 modification of the ether. The stresses and strains in this 

 medium manifested themselves as electric attraction and repulsion; 

 the short waves were light and heat, and the longer waves were 

 used in wireless telegraphy. All electrical charge and discharge 

 were essentially that of a Leyden jar, and when the coatings of a 

 charged jar were connected by a wire the discharge consisted of a 

 series of decadent electrical oscillations or rushes of electricity 

 along the wire, many reversals and re-reversals of the charges 

 occurring in the exceedingly short period of duration of the 

 spark. The lecturer went on to deal with the phenomena of 

 electric oscillations and the methods of producing these. The 

 manner in which resonance occurred and operated in the sphere 

 of mechanics, sound, and electricity respectively was next 

 referred to, and was followed by a description of electric oscilla- 

 tions in wires, and the nature and production of waves in ether. 

 The lecturer, having lucidly described Hertz's experiments, the 

 slides and experiments shown at this stage being particularly 

 interesting, proceeded to discuss the detection of waves and their 

 application to wireless telegraphy, Having described in detail 



