ON STANDARDS FOR USE IN ELECTRICAL MEASUREMENTS. 



153 



The value found originally for the capacity of No. I. was •021024 

 microfarad ; it would appear therefore that it may be slowly increasing ; 

 the capacity of No. II. has been changed by being taken to pieces, and 

 from •022515 to 021391. 



The two condensers were also compared, directly assuming the value 

 of No. I. to be •021050 ; that of No. II. was found to be •021390— 

 practically the same value as that given by the commutator. 



As a further check on the values a mica condenser was compared 

 with the two in the nsual way. The values found were : — 



Table XIII. 



In March 1892 the insulation of the condensers was tested by the 

 Secretary and Mr. A. S. Bowley ; they were both found to lose rather less 

 than -jj-i^ of their charge per one minute. A divided condenser, Elliott 

 No. 144, No. 3, was compared ; the results are interesting as showing 

 the effect on the capacity of the time of charging, and are given in 

 Table XIV. 



Table XIV. 



The first observation in each case marked as 0* was made by con- 



