124 THE ROYAL SOCIETY OF CANADA 



parallel lines, the line for "meter before gauge" lying above the line 

 for "gauge before meter." The difference is perhaps due to the fact 

 that the gas meter registers correctly only when its outlet pipe is 

 open to the air. More work may be done on this point,, using a 

 capillary tube without the projecting ends ^C, DB, so that the whole 

 of the pressure fall may lie in the capillary tube CD under test. 



University of Toronto, 1920. 



