212 OF ELECTRICITY. CHAP. 7. 1 



curiously curved, resembling architectural orna- 

 ments; a circumstance still more difficult of 

 explanation. Future and repeated observations 

 may, possibly, in the course of time, throw 

 some light on the causes of these varieties. 



To return to the Sondercloud : if it really 

 exist with a strong electric charge, and be very 

 retentive of it, the latter circumstance, probably, 

 results from its being surrounded by dry air, 

 which is not a conductor. Conformably to 

 this view, I have noticed the loose indefinite 

 features, which accompany damp air, and 

 appear, in the intervals of common Showers, to 

 be of short duration: and that 'they have passed 

 to a sort of confused cirrus or cirrostratus, 

 while the dense and compact aggregates, which 

 compose the stormy features, are often of long 

 duration ; and I have not observed this dense 

 feature to form itself into Curlcloud and 

 Wanecloud in the manner afore described. 

 The densest nimbi, and the hardest Thunder- 

 storms, often follow the conjunction of this 

 feature of Sondercloud with the other modifi- 

 cations. Another distinction is also worthy of 

 remark : the loose flimsy and transient features 

 of cirrocumulus, often appear above, when 

 cumuli are rapidly flying along in a gale 



