1905.] 



PUBLIC DOCUMENT — No. 38. 



25 



Takle V. — Records showing the Electrical Potential {Volts) taken from 

 an Elm Tree and from Free Air — Continued. 



[Collector III., 12 feet high, in Norway spruce. Nos. IV. .and V., readings taken from 

 copper plates in soil. Time of observation, i) a.:\i.] 



