132 



ROYAL SOCIETY OF CANADA 



TABLE XI— Continued 



Time 



Dec. 18th I 



and 19th, I 



1908 I 



Temp. 



Bar. 



A small glass u-tube mercury manometer was also sealed into the 

 side of the receiver to give indication of any air leak in the vessel. 



In preparing for the observations, care was taken to thoroughly 

 clean the inside of the receiver and freshly filtered air was introduced 

 into it to a pressure sUghtly greater than atmospheric pressure. This 

 slight excess of the inside pressure over that of the atmosphere out- 

 side produced a difference of level in the two arms of the mano- 

 meter. From the manner in which this difference of level followed 

 the changes in the barometer it was soon seen that the receiver was 

 air-tight, and therefore in the condition desired for the observations. 



