Professor GErsted on irater-Spuuts. 53 



long continue to be the case, if we desire a perfect explana- 

 tion of the first change in our atmosphere by means of which 

 a Avater-spout is caused. It appears, that, owing to the over- 

 strained regard paid to this higher demand, which must so 

 often be left unsatisfied, the simpler but yet fruitful labour 

 has been neglected, of bringing together the remarkable appear- 

 ances with which observations on the subject have furnished 

 us, and by this means ascending gradually from the effect to 

 the proximate cause, until at last we may perhaps succeed 

 in ascertaining clearly the bearings of the whole matter, al- 

 though, at the same time, much, in reference to the ultimate 

 cause, may still remain wanting to satisfy our desire of in- 

 formation. It appears to me, that, by following this less am- 

 bitious course, we may advance nearly as far in om- knowledge 

 of water-spouts as we have done in respect to thunder-storms, 

 wind, rain, and many other natural phenomena ; inasmuch as 

 we can probably specify with tolerable certainty the po\^'er by 

 which they are produced, althovigh we cannot accurately de- 

 termine all the circumstances connected with the principles 

 by which the action is caused at a given place Avith a given 

 degree of intensity. 



I have collected the chief features for my description of the 

 phenomenon, from nvimerous scattered descriptions, for Avhich 

 Ave are indebted to observers in different ages and in different 

 ([uarters of the globe ; and I venture to hope that the com- 

 bination of facts thus elicited Avill keep us free from many 

 errors, in which most of those have been involved, Avho have 

 hitherto endeavoured to explain AA'ater-spouts. It is quite 

 possible that I may have overlooked circmnstances Avhich 

 Avould tend to explain the subject, or that I may have misun- 

 derstood some of the facts contained in the descriptions ; but 

 this can easily be remedied by the obliging communications 

 of others, Avhenever Ave possess a general analysis of the facts. 

 General Nature of JVater-Spoiits.—The Avater-spout is a 

 strongly agitated mass of air, which moves over the surface of 

 the earth, and revolves on an axis, of which one extremity is 

 on the earth and the other in a cloud. From this cloud a 

 continuation proceeds downwards, Avhich forms the upper por- 

 tion of the water-spout ; Avhile the lower portion, besides air, 



