THE 



AMERICAN JOURNALOFSCIENCE 



[FOURTH SERIES.] 



Art. XII. — Recent Observations in Atmospheric Electric- 

 ity ;*by P. H. Dike. 



It is somewhat difficult to give a satisfactory resume of recent 

 work in Atmospheric Electricity which can claim to be complete 

 and at the same time strictly up to date, since aside from the 

 four or five centers from which emanate most of the contribu- 

 tions to the advance of the subject, work is frequently coming 

 to light from unexpected sources. 



We have been in the habit of looking to Elster and Geitel, 

 Gerdien, Ebert, and a few others in Germany, to the Caven- 

 dish Laboratory in England, and to Rutherford and his fol- 

 lowers at McGill University, Canada, for most of the work in 

 Atmospheric Electricity, but of late other experimenters have 

 begun to enter the field. 



Sot very much has been done as yet in this country along 

 these lines, and what has been done has been scattering and 

 desultory for the most part, consisting of the work of an indi- 

 vidual here and there. There has been no such extended and 

 persistent study of the subject, and such careful experimenta- 

 tion as has been going on in England and Germany for some 

 years, and which has yielded so many important and interest- 

 ing results. For this reason most of the work referred to will 

 necessarily have been done in foreign laboratories. The field 

 of research in Atmospheric Electricity is a broad one and pre- 

 sents numerous complications of a most troublesome sort, 

 which offer to the observer abundant opportunity for the 

 exercise of his ingenuity. 



The earliest known and most thoroughly studied of all the 

 phenomena included under the head of Atmospheric Electricity 



* Presented before the Philosophical Society of Washington, October 24, 

 1908. 



Am. Jour. Sci.— Fourth Series, Vol. XXVII, No. 159.— March, 1909. 

 14 



