Tornado in N. E. part of Ohio, Feb. 4, 1842. 287 
objects upon one side, if revolved about the 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. On the southeast half of the track the wind began 
on an average blowing towards N. 14° E., and ended N. 57° Ey 
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, 334° E. The destruction of timber on the northwest 
half was estimated to be double of that on the southeast. Per- 
haps this might be. oceasioned by a wind blowing with one half 
greater velocity. ‘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 js 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 8. 334° 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 tions on page 285. A little farther to the left, the 
