Observations on a Hurricane in Ohio. 375 
trees which fell near the middle of the track. Take the case of the 
four trees I have mentioned in front of the house G. | They lie par- 
allel to each other, side by side, and fell nearly at right angles to the 
track of the hurricane. Yet the tops of two of them incline to the 
north, and those of the other two to the south. Here there were 
two winds which blew, we cannot suppose simultaneously, but suc- 
cessively, from opposite points of the compass at the very same spot, 
and the two winds must have succeeded each other at an interval 
not exceeding a minute, for the violence of the hurricane was past 
in about that time. The preceding, moreover, is a phenomenon which 
occurred not in one spot merely, but all along the centre of the 
track. Every where there is the same evidence of two currents in 
exactly opposite directions, having passed over precisely the same 
spot. I know of but one supposition which will explain all these phe- 
nomena ; viz. that the air near the centre of the track had a whirl- 
ing motion. A tree then which was levelled as this whirl was ap- 
proaching it, would be turned to the right for example ; and another 
which fell as the whirl was receding would be inclined to the left; 
so that we might have trees side by side, lying parallel to each 
other, but with their tops turned in opposite directions conformably 
with the observations. It appears, however, that this whirl did not 
extend over the breadth of the entire track, for then trees must have 
every where fallen, occasionally at least, parallel to the track, a fact 
which has been observed only near the middle of the path. 
_ We are now I think, in a situation to explain nearly all the phe- 
nomena which have been observed. ‘The wind blew from the op- 
posite sides of the track, and doubtless from every point of the com- 
pass, towards some point in the centre of the track; here the wind 
rose violently with a gyral motion. This vortex itself had a rapid 
motion from west to east, sweeping along over the middle of the hur- 
ricane’s path. ‘Trees then upon the borders of the track would every 
where fall towards this vortex. Those which were prostrated as the 
vortex was approaching, would have an inclination to the west ; but 
those which fell as the vortex was receding, would be found inclined 
to the east, and we should no where find trees falling outward from 
the track or even parallel to it. All this is in exact conformity with 
the observations. We may now, moreover, explain a fact which at first 
view might have seemed quite anomalous, viz. that the house D was 
carried in the direction of the barn, while a tree behind the barn fell 
towards the house. At the surface of the earth the wind must have 
