532 On the Vitreous Tubes found near Drigg^ in Cumberland. 



The sand hillocks of Drigg, though of inconsiderable elevation, 

 are not unfavourably situated for promoting a discharge, since they 

 present themselves as the first and highest object in front of the 

 marshes of the Irt to clouds coming from the sea. Should the ex- 

 planation of the Sand Tubes, which is now offered, be admitted, 

 some judgment may be formed of the intensity of the heat developed 

 in great electrical explosions. 



