CH. IX.] 



A CHORD EXPERIMENT 



93 



One of the first direct determinations of the aver- 

 age charge on a gaseous ion was made by Professor 



H 



FIG. 14. 



Townsend (Philosophical Magazine, February, 1898), 

 his method consisting in bubbling newly-prepared 

 gas through water and measuring the charge on each 

 droplet. The deduction must be regarded as rather 



