JOURNAL OF THE COLLEGE OF SCIENCE, IMPERIAL UNIVERSITY, 



TOKYO, JAPAN, 



VOL. XVI, ARTICLE 7. 



Studies in Atmospheric Electricity. 



By 



Y. HOMMA, BigaJmshi. 

 Professor of Physics in First High School, 



With Plates I— IV. 



GENERAL DESCRIPTION. 



The facts to be discussed below have been obtained chiefly from 

 the " Report on Observations in Terrestrial Magnetism and Atmos- 

 pheric Electricity made at the Central ]\leteorological Observatory of 

 Japan for the Year 1897," though some are from the original photo- 

 graphic records preserved in that observatory. The observatory, 

 whose coordinates are = 35° 41' X., /'.= 139° 45' E., occupies a portion 

 of the old castle of Yedo, and thus stands pretty well out of the 

 direct effect of tlie dust and smoke of the city. The collector for 

 atmospheric electricity is a water-dropper whose nozzle is 2 m. from 

 the wall of the building and 1.7 m. above the ground. The photo- 

 graphic record is given by a Kelvin-Mascart's self-recording electro- 

 meter. The time refers to the central standard time, i.e. the mean 

 time for the meridian 1.35° E. Other details with regard to the 

 observation and reduction will be found in the first pages of the 

 Report. 



