Tornado in N. E. part of Ohio, Feb. 4, 1843. 287 



objects upon one side, if revolved about tbe central line, should 

 answer equally well for the other side of the track. How far 

 this is conformable to observation has already been seen. The 

 entire range of prostrate trees on the right side is 90°, on the 

 left 360°. Such a supposition then in the present instance is 

 wholly inadmissible. 



For determining, the motion of the wind we have the follow- 

 ing data. Oa the southeast half of the track the wind began 

 on an average blowing towards N. 14° E., and ended N. 57° E. 

 On the northwest half, the wind began N. 55° W. ; passed 

 through N. 16° E. ; and ended N. 62° E. The tornado ad- 

 vanced N. 33^° E. The destruction of timber on the northwest 

 half was estimated to be double of that on the southeast. Per- 

 haps this might be occasioned by a wind blowing with one half 

 greater velocitj''. The same inequality in the wind's violence is 

 indicated by the buildings. On the southeast half of the track 

 no building suffered any greater damage than the loss of a roof. 

 On the northwest half, every building except Dean's barn and 

 corn-house was totally demolished, and these are supposed to 

 have been saved by the weight of their load. Let the black ar- 

 rows on Fig. 4, Plate IV, represent the quantity and direction of 

 the forces in question. Each of these forces is the resultant of 

 two others, one the progressive motion of the tornado, and the 

 other its own peculiar motion. The latter was evidently much 

 the greatest. From the extremity of each of the arrows set off 

 in a direction S. 33^° W., a line representing the progressive 

 motion. The dotted arrows will represent the motion peculiar 

 to the tornado. With these for my guide, I have drawn lines 

 representing the supposed circuit of the wind. Near the point of 

 convergence of these directions the wind must have risen with 

 prodigious violence. According to this diagram, the wind on the 

 right side of the track must have begun generally to blow about 

 N., and ended N. 60° E. At no place could the wind have 

 blown more than a few degrees west of north ; at no place could 

 it have been quite east. Thus on the right side, the entire range 

 of directions is included within 90°. On the left side of the cen- 

 tral line, the directions comprise every point of the compass. On 

 the line A C, the bearings commence N. 55° W., pass through 

 N. 16° E., and end N. 62° E. This corresponds with the mean 

 of the observations on page 285. A httle farther to the left, the 



