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THE ROYAL SOCIETY OF CANADA 



10°C. below zero, so that the ice cyHnders prepared in this way were, 

 when finished, one piece of ice and were air-tight apart from any 

 porosity which the ice possessed. The appearance which the Wolff 

 Electrometer and the cylinders of zinc and ice when mounted on the 

 Wilson electrometer presented is shown in Figs. 3, 4 and 5. It should 



Fig 3. 



be mentioned that the measurements with the ice receivers were made 

 when the temperature ranged from 1 °C. below zero to 10°C. below zero. 



III. RESULTS AND THEIR DISCUSSION. 



Numerous sets of readings were taken at the three stations and a 

 summary of the final results compiled from these is given in Table I. 



Table I. 



Ionisation of Air. 



Summary. 



Zinc receiver in Library 



Wolff Electrometer in Library 



Zinc receiver at House 



Wolff Electrometer at House 



Zinc receiver on Bay 



Wolff Electrometer on Bay 



Tap water ice receiver at House. . . 

 Tap water ice receiver on Bay. . . . 

 Distilled water ice receiver on Bay 



