Rotary Action of the Providence Tornado. 265 



" cone ;" showing that the whirlwind often acts on a large area, 

 with great force, externally to the lower part of the visible cone, 

 or the column of vapor at its axis. Moreover, the substances 

 which by the center of the tornado were "uplifted high in the 

 air," were " left to fall from the outer edge of the black conical 

 cloud."* 



Mr. Allen says further, " The progress of the tornado was 

 nearly in a straight line, following the direction of the wind, 

 with a velocity of perhaps eight or ten miles per hour. Near as 

 I was to the exterior edge of the circle of the tornado, I felt no 

 extraordinary gust of wind ; but noticed that the breeze contin- 

 ued to blow uninterruptedly from the same quarter from which 

 it prevailed before the tornado occurred. I also particularly ob- 

 served that there was no perceptible increase of temperature of 

 the air adjacent to the edge of the whirlwind, which might have 

 caused an ascending current by a rarefaction of a portion of the 

 atmosphere." 



Soliciting a careful attention to the observations of Mr. Allen, 

 who is well known for his intelligence and his habits of correct 

 observation, I proceed to give some account of my own examina- 

 tions of the traces of this tornado. 



* Mr. Allen states that the form of the cloud and of the cone of vapor depend- 

 ing from it so nearly resembled the engraved pictures of water-spouts' above the 

 ocean, that he should have come speedily to the conclusion that one of these ' wa- 

 ter-spouts' was approaching, had he not been aware that " this phenomenon occu- 

 pied a space in the heavens directly above a dry plain of land." Perhaps it might 

 be inferred that Mr. A. had partaken of the too common notion, that the misnamed 

 water-spout is, or should be, literally b. spout of water. This phenomenon, so much 

 talked of among mariners, proves to be nothing more nor less than the visible in- 

 verted " tapering cone of vapor" or condensation, noticed by him as " extending 

 from the cloud to the surface of the earth," at the axis or ascending portion of the 

 whirl; if we may at all rely on the results of extensive examinations and compari- 

 sons of the accounts of ' water-spouts' and their effects. The same appearance 

 was observed in the New Brunswick tornado by experienced seamen navigating 

 the Raritan river, who at once pronounced it to be a water-spout, and took their 

 measures accordingly. It is probable, however, that most of the ' water-spouts' 

 noticed at sea, are inferior in size and energy to these destructive tornadoes. 



A ' water-spout' was seen by Messrs. Tyerman and Bennett near Borabora in 

 the Pacific, which extended neatly horizontally from one cloud to another directly 

 over their heads; and no harm done ! The most credulous will hardly conceive 

 this to have been a column of water, or even approximately such : besides, no 

 sea-water has ever been known to fall from the clouds. Similar ' spouts' have 

 been seen by others ; and I once beheld a magnificent example of this kind, in 

 one of the interior towns of Connecticut; which probably indicated an axis of ro- 

 tation nearly horizontal. 



Vol. xmi, No. 2.— July-Sept. 1842. 34 



