32 



THE ROYAL SOCIETY OF CANADA 



IV. Measurements on land. 



At various times previous to and succeeding the two voyages 

 as well as at times in the interval between them readings were 

 taken with the instrument at a number of points at or near Toronto, 

 and also at a number of places at the other side of the Atlantic. These 

 are summarized in Table III, and along with them are given the 

 readings taken at a number of places with the Wilson Compensating 

 Gold leaf Electrometer. 



TABLE III. 



Measurements of penetrating radiation at stations on land. 



From the numbers given it will be seen that the readings with both 

 instruments were practically the same at Midlothian, Scotland, at 

 Cambridge, England, and at the Physical Laboratory, Toronto. This 

 combined with the high value obtained for the ionisation on the 



