CHAP. 7- 2. OF ELECTRICITY. 215 



certainly different; and mischievous effects 

 generally "happen with that kind of which the 

 intonation is single, or of very short duration, 

 and which happens soon after the flash.* But 

 these circumstances may be attributed to the 

 nearness of the cloud to the object destroyed by 

 the Lightning. There are, however, differences 

 in the appearance of Lightning: it looks at 

 some times much brighter, and of a bluer light, 

 than at others. This difference of colour is 

 most remarkable in the vespertine fulgurations 

 in summer ; which form the subject of the next 

 section. 



I cannot omit to mention one circumstance, 

 which seems rather contrary to my explanation 

 of the differences of claps of Thunder, and 

 rather favours the hypothesis of M. Van Mons, 

 namely, that the two kinds of Thunder often 

 happen, and, indeed, alternate with each other 

 in the same Storm. 



The Meteors or balls of fire which occasionally 

 shoot from Thunderclouds during a tempest 



* I noticed both kinds in the violent Storm of Thunder jfhd 

 Lightning, in which we were caught while travelling from 

 Gex to Nyon, in Swizzerland, last summer,, before alluded to. 

 The Storms at this period were mischievous in many and 

 very distant parts of Europe. 



