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THE ROYAL SOCIETY OF CANADA 



the tube and the average taken as the average radius in the portion 

 of the tube CD. The length CD is measured to the nearest millimetre 

 from junction to junction, making a careful estimate of the position 

 where the effective length of the capillary tube begins and ends. 



The readings for three tubes A,B, C, in use in my laboratory and 

 made up without any special selection of the tubing are shown in 

 Table I. The readings were taken by the author with a stopwatch 

 and were not duplicated. 



TABLE I 



The dimensions of the tubes (taken by the author without 

 duplication) are as given in Table II. 



