Chap. 6".] Ajcending and defending Water-Jpouts. 357 



moft formidable phenomenon, and is indeed capable 

 of canfing great ravages. It commonly begins by a 

 cloud, which appears very fmall, and which mariners 

 call the fquall, which augments in a little time into an 

 enormous cloud of a cylindrical form, pr that of a 

 reverfed cone, and produces a noifc like an agitated 

 fea, fometimes emitting thunder and lightning, and 

 alfo large quantities of rain or hail, furBcient to in- 

 undate large veffels, ovcrfet trees and houfes, and 

 every thing which oppofes its violent impetuofity. 



Thefe water-fpouts are more frequent at fea than 

 by land, and failors are fo convinced of their dan- 

 gerous confequences, that when they perceive their 

 approach, they frequently endeavour to break them by 

 firing a cannon before they approach too near the 

 fhip. They have alfo been known to have committed 

 great devaluations by land : though, where there is no 

 water near, they generally aflame the harmlefs form 

 of a whirlwind. 



In accounting for thefe phenomena upon electrical 

 principles, it is obferved, that the effluent matter pro- 

 ceeds from a body actually electrified towards one 

 which is not fo ; and the affluent matter proceeds from 

 a body not electrified towards one which is actually 

 fo. Thefe two currents occafion two motions anala- 

 gous to the electrical attraction and repulfion. If the 

 current of the effluent matter is more powerful than 

 the affluent matter, which in this cafe is compofed of 

 particles exhaled from the earth, the particles of va- 

 pours, which compofe the cloud, are attracted by this 

 effluent matter, and form the cylindrical column, called 

 the defcending water Jpcut ; if, on the contrary, the 

 affluent matter is the ftrongeft, it attracts a fufficient 

 quantity of aqueous particles to form gradually into 

 A a 3 a cloud, 



