ISO 



ROYAL SOCIETY OF CANADA 



being supported by insulating materials in position in the cylinder. 



The insulated electrode in the receiver was protected by an earthed 



guard tube which was also sealed .in position and finally all the joints 



of the cylinder were made air-tight by means of either solder or marine 



glue. 



When the cylinder was placed in position above the electroscope a 



small spring made metaUic contact between the two sections of the 



electrode. 



TABLE XI 



