148 Measuring Surface- Tension and Angles of Contact. 



The curves (fig. 2) were obtained by plotting r against R for 

 water, glycerine, olive oil, turpentine, and mercury. It will 



Fii 2. 



2 3 



Radius of Tube. 



4 mm 



be noticed that all appear to approach the origin at an angle 

 of 45° with the exception of mercury. This points to a 

 zero angle of contact with all except mercury. Mercury 

 gives an angle of nearly 41°, or rather, a little greater than 

 180°-41°=139°. 



University College, Galway 



