52 



Mr. A. M. Worthington on the 



[Dec. 18, 



When a guiding cylinder of cardboard, in wliich the iron plate could 

 be moved like a piston, was used in order to ensure the plate being 

 lifted vertically, the friction against the cylinder prevented the plate 

 being lifted so quickly, and this at once influenced the number of 

 drops, as will be seen in the following table : — 



Method of liberation. No. of drops. Remarks. ' 



With well-oiled guiding ring. ... 16 Regular. 



16 

 16 

 15 



With guiding ring not oiled. 



Lifted slowly on purpose. . 



,, rather slowly on purpose 

 Very slowly on purpose 



10 5 in opposite quadrants. 

 13 

 10 

 10 



7 Arranged 

 thus : 



5 Nearly regular. 

 3 Regular ? 



2nd Groove. Diameter (d)— 1*04 millims. 

 Principal radius (R) = 12 5 ,, 



Method of liberation. No. of drops. 



Glass plate, rapid lifting 17 



• 18 



16 



16 



Mean 17 



Without special precaution as to speed 11 



n )> 13 



5> J> >> 12 



» ..... 14 



»> j> )? 11 



Lifted slowly on purpose 10 



