CHAP. 7- 7- OF ELECTRICITY." 229 



and the other minus or negative: and the 

 metallic clapper moving rapidly from one to the 

 other, to equalize the two electricities, a pulsa- 

 tion is produced, and the bells ring. Neither 

 the heat or cold, dryness or moisture of the 

 atmosphere, appear to have any considerable 

 influence on the action of this instrument ; but 

 it is considerably altered by peculiarities in the 

 electric state of the atmosphere. The prevalence 

 of cirri ramifying about the sky in various 

 directions, and accompanied often by other 

 modifications, by dry easterly and changable 

 winds, and by numerous small meteors of an 

 evening which appear to indicate a disturbance 

 in the atmospherical Electricity, I have noticed 

 to be accompanied by an irregular action of the 

 Electric Column of M. De Luc ; the bells ring 

 at intervals, and with a kind of hurried pulsa- 

 tion. When such weather as I have described 

 is followed by Rain, the bells have been found 

 silent. There are also other varieties in the 

 kind of pulsation of the bells ; sometimes they 

 ring weak and regular, sometimes weak and 

 irregular, sometimes strong and regular, at 

 others strong but irregular ; the intervals of 

 quiescence are sometimes of longer duration 

 than at others. These minute variations are 

 probably connected with peculfarities in the 



