286 Tornado in N. E. part of Ohio, Feb. 4, 1842. 



Mean of the bottom trees N. B5° W. ; top trees N. 62° E. : 

 intermediate trees N. 16° E. Here is a remarkable uniformity 

 which cannot be ascribed to accident. The bottom tree points 

 invariably westerly, and the top tree easterly. To this there is 

 no exception. The directions of the intervening trees are inter- 

 mediate between the extremes, passing round in the order west, 

 north, east. To this rule there are only four exceptions marked 

 with an asterisk. The direction of the third tree in the third 

 group differs 30° from that of the fourth ; the third tree in the 

 sixth group differs 38° from the second ; the third tree in the 

 eighth group differs 65° from the fourth ; the fourth tree in the 

 fourteenth group differs 80° from the third. These are the anom- 

 alies 30°, 38°, 6.5°, 80°. How are they to be explained? Do 

 they invalidate the inference which naturally follows from the 

 other bearings, that the wind on this part of the track revolved 

 in the direction west, north, east? I think not. For first; the 

 exceptions are but four to fifty two, or one to thirteen cases. Sec- 

 ond, it is not to be supposed that the rotation of the wind was 

 absolutely uniform like the motion of a clock. In the case of 

 what passes for a rectilinear current, the wind often veers by jerks 

 back and forth from its mean direction through an arc varying 

 from 50° to 90° in five minutes. The 7nean variableness, at 

 Hudson for an interval of five minutes is 42° ; so that it could 

 not be deemed surprising if objects prostrated by what is called a 

 rectilinear current should often differ in their directions by this 

 amount. Bat thirdly, the direction of the principal roots of a tree 

 will somewhat influence its fall ; and finally where thousands of 

 trees are falling at the same instant, as in the present case, in a 

 dense forest, their tops must frequently interfere, and a tree be 

 turned greatly from the position it would otherwise occupy. The 

 force of this last remark will be perceived when it is considered 

 that the tornado had entirely passed in seventy five seconds, and 

 its most destructive violence probably did not exceed fifteen sec- 

 onds. It should however in candor be admitted that some of the 

 disturbing causes here named would have less influence, from the 

 extreme violence of the wind. 



If the motion of the air were merely centripetal, that is. directed 

 in right fines from the circumference of the tornado to the centre, 

 then the phenomena on the two sides of the track should be per- 

 fectly symmetrical^ and a diagram of the directions of prostrate 



