Remarks en IJghtning Rods, 



loi 



ftance colder than tlie air, we obferve them fweat, as the com- 

 mon e:^preffion is, which is nothing more than the falling of 

 the water contained in the flirrounding air, brought within 

 the lj>here of the cold body ; thus the watery particles of the 



breath, in warm weather, are inftantly difTolved on refpiration ; 

 but in cold weather, they are vifible, and in extreme cold, fall 

 in grofs particles on the furrounding objeds. 



After feveral days of fummer's heat, a large fpace of air be- 

 ing in this heated flate, clearly eftablifhes this hypothecs, and 

 fliews us. the caufe of thunder ftorms. A column of cold air 

 burfting into the ratified fpace, deprives the warm air of the 



power to fuflain the water before 



takes place, which terminates in rain 



ivilible ; c 



Dry air, I 



[idenfat 



be a non condudor, or at leaf! a very bad 



one, and that air 



combined with a portion of 



may be rendered 



y 



poor one, by the application of heat fufiicient to diiTolve that 

 water ; but when the air in a given fpace, is deprived of heat 

 by a column of cold air coming in contad, and the watery 

 particles condenfed, they become a conductor, and of courfc 



will receive the eleclrical fluid 



Thus this column of cold 



generating moifture, as above Hated, pafles through a region of 



heated or di 



and by it is in a degree infulated 



and 



the fame tim.e receives the fmall portion of ekarical fluid 

 tained therein. A cloud thus formed has a fphere, and w 

 that fphere, cert^m Jirata differently charged at differ 



but they appear to me of fo fliort dv 



preclude 



ii 



ffity 



