266 On Water-Spouts. 



The direction of water-spouts from southwest to northeast, 

 may be ascribed to the circumstance of this wind preceding their 



occurrence. 



Water-spouts are often bent ; and this must arise from those 

 winds which prevail at. various heights above the earth, and 

 which transport the entire masses of air m which the whirlwinds 

 are contained. There is nothing in such a case to prevent one 

 whirlwind continuing to act on the other. 



It has been maintained that sharp cannon shots can drive a 

 water-spout asunder. It is by no means inconceivable that balls 

 which strike in such a manner that their direction is the opposite 

 of the circular movement of those portions that they meet, can 

 produce such an effect j but I do not venture to decide if the ac- 

 counts we possess are sufficient to prove the actual occurrence of 



such a consequence. 



In considering the water-spout^ we have endeavored to arrive 

 at its proximate causes from the effects which have been observed 

 and recorded ; and we have ascertained that a whirlwind which 

 begins in the higher regions of the air, and becomes expanded as 

 it descendsj constitutes the essential element of the phenomenon* 

 It will, however, be further asked, What is the cause of this vor- 

 tex? We perceive plainly that a v/hirlwind can be produced by 

 two currents of air following parallel courses, but flowing in op- 

 posite directions. There is nothing to prevent us from assumin 



or 



the existence of such currents in the higher regions of the atmos- 

 phere. They must often occur there while the air beneath is 

 perfectly tranquil ; at least, during an aerial voyage, a whirling 

 cloud was met with ; but we must also admit that we are in pos- 

 session of no evidence of such air-currents actually existing at 

 the period when a whirlwind is formed. But still, that this is 

 the case seems very probable, wheu we reflect that they must be 

 of frequent occurrence, and that they are capable of producing 

 the effe.ct we have said might be ascribed to them. 



Experience teaches us, that such opposite streams in the higher 

 regions of the air often contend with each other, while profound 

 repose pervades the lower strata. We know also that the oppo- 

 site currents produced by the inequality of temperature over the 

 land and sea, often extend upwards to a great height, and are 

 there in a state of great commotioUj while all is tranquil beneath. 



