Professor Qirsted on Water-Spouts. 61 



(= .22 English.) At 8 o'clock the water-spout made its ap- 

 pearance, and about noon the quicksilver had risen to the 

 same height at which it stood in the morning. This result is 

 sufficiently remarkable to make us desirous of possessing far- 

 ther observations of a similar nature ; but, as I have already 

 said, my notes contain no others ; and on referring to the books 

 in my possess!^, I have found no information on this subject. 



Formation and Phenomena of IFater- Spouts. — In most ac- 

 counts it is stated that water-spouts are formed from above. 

 Some observers, however, expressly say that they have seen 

 them in the act of being formed from below. Michaucl, who, 

 in 1789, observed some water-spouts in the harbour of Nice, 

 laid much stress on this commencement from the sm'face of the 

 sea ; it will appear, however, from what is to follow, that this 

 only seems to be the case, and proceeds from the circumstance 

 that the whii-1 of wind which forms it, so long as it is not im- 

 pregnated with vapour or drops of water, is not visible. 



When a water-spout begins to be formed over the sea, there 

 is generally to be observed a cu'cular portion of the surface of 

 which is uneven, and has a black appearance. Soon after, the 

 water is elevated in the form of a pillar, in which a violent in- 

 ternal movement is observable, the height being several fa- 

 thoms. It foams, and produces drops of water above, which it 

 scatters in great quantity on all sides, so that it distinctly ex- 

 hibits an ascending and descending course, which moves in pa- 

 rabolic curves, like spring-water ascending in a slanting direc- 

 tion. The internal movement has been compared to boilmg, 

 and it has been believed that tliis idea was confirmed by the 

 mass of vapour and fog which generally floats above the wa- 

 ter-spout. De la Nux, however, who, for forty years, lived in 

 the Island of Boiu"bon, where water-spouts are extremely com- 

 mon, maintains that this vapour is only apparent, and that it 

 proceeds from the great number of drops of water spurted 

 about. He also says, that, in order to be convinced of this, it is 

 only necessary to see the phenomenon in a proper light. It 

 would, however, be too bold to assert that this is always the 

 case. It is not impossible that vapours may be formed round 

 the agitated water, if that water possessed a lower temperature 

 than the tur, and thus cooled the moisture contained in it. That 



