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ATMOSPHERIC ELECTRICITY. 



On the Electricity of the Atmosphere in dear Weather. Connexion between Electricity and Me- 

 teorology. Apparatus for observing the Electricity of the Atmosphere. Insulated elevated Rod. 

 Portable Apparatus made of a fishing Rod. Saussure's Electroscope and his Mode of estimating 

 the Value of the Divergences. Occasional Use of the Galvanometer. The ordinary State of /he 

 Atmosphere. Volta's Theory of the Origin of Atmospheric Electricity. Inadequacy of the The- 

 ory of Chemical Origin. The Author's Suggestion of the probable Influence of Friction. Dinr- 

 nal Variation of the Electricity. Periodical hourly Variation. Representation of the R ate of Va- 

 riation. Maxima and Minima at a given Parallel. Schiibler's Observations. Annual Variation 

 of tfie Electricity. Variation of the daily Maxima and Minima. Arago's Repetition of Schiibler's 

 Observations. Local Variations of the Electricity. Influence of particular Localities. Buildings, 

 &c. No satisfactory Explanation yet given of the Variations. Correspondence between Electric 

 and Magnetic Variations. Becquerel's Explanation of the Phenomena of Variation. Distribution 

 of Electricity of the Air. Negative State of the Earth. Character of the lower Stratum of Air. 

 Increase of Electric Charge in the higher Strata of Air. Decrease in the lower Strata. Compar- 

 ative Electric Character of different Strata. Formulae for the comparative Electricity of two 

 Strata. Electricity of the Air in clouded Weather. Preliminary. Schiibler's Observations. Ta- 

 ble of Observations explained 



