On Waier-Spoiits. 253 



that the middle portion of the water-spout is surrounded by a 

 ■whirlwind, which does not allow of observation, owing to its 

 containing no opaque particles. 



Color and Transparency of Water- iSp outs. — The color most 

 frequently assigned to water-spouts is grey, dark blue, also dark 

 brown, and fire red ; from which it would seem that the colors 

 are the same which the clouds assume in their different states of 

 illumination. 



The middle portion of water-spouts is often transparent, but 

 this holds good only in those which occur over water. One 

 water-spout was noticed whose middle portion was opaque while 

 it traversed the land, but became transparent when it proceeded 

 over a river. The transparency of this portion at the sea has 

 sometimes been observed to so great an extent, as to allow of 

 those clouds being seen through it which were lighted up by the 

 sun. When an opaque water-spout begins to become feeble, the 

 cloud-like portions, which had descended into it, retire, and as the 

 drops of water, the foam, the dust, &c. which caused the opacity, 

 are no longer driven upwards to so great a height, the middle 

 portion becomes transparent. 



Duration and Movements of Water-Spouts. — Water-spouts 

 generally last longer the larger they are ; but they rarely continue 

 for half an hour, and there is hardly one example of an hour's 

 duration. 



Water-spouts seldom, if ever, remain the whole time at one 

 place. There is great inconstancy in their rapidity and direc- 

 tion. They sometimes have so great a rapidity as to move seven 

 or eight German miles (thirty two to thirty seven English miles) 

 in an hour ; at other times they advance so slowly, that pedestri- 

 ans can easily follow them, and occasionally they remain quite 

 stationary for a time. Their course is sometimes quite straight 

 for a long distance, but not unfrequently it is interrupted ; in 

 some instances it is zig-zag. Their course, however, has for the 

 most part a principal direction or bearing. It has been asserted 

 that the direction of water-spouts is most frequently from south- 

 west to northeast, and certainly the data hitherto collected go to 

 confirm this opinion. 



Water-spouts do not remain uniformly at the surface of the 

 earth, but alternately rise and fall ; and hence we see, that, dur- 

 ing their progress, they have in some places, torn up trees by the 



