be 
74 On the Whirling Action of the 
The facts here considered are too important to be overlooked, 
and seem fully to establish both the whirling action and the 
course of rotation. 
9. If a rotative action be exhibited, the mean directions of all 
eno on each of the two opposite sides, will differ 
‘greatly in their respective inclinations to the line of progress, and 
the mean direction of those on the reverse side will be found 
more backward than on the opposite side, where the rotative 
course coincides with the progressive action. 
In the case before us, the mean direction of all the prostrations 
on the right side of the track is found to incline 52 degrees in- 
ward from the line of progress. The course of the tornado is 
here taken to be east ; although for the last half mile its course 
had been a little north of east. On the left side, the mean direc- 
tion is found to be 8. 3° W., or 93 degrees inward and back- 
ward ; a difference in the mean inclination from the course on 
the two sides of 41 degrees.* 
If we now take the indications afforded by the two exterior 
portions of the track, to the width of five chains on each side, 
where the effects are more distinctive in their character, we find 
on the right side a mean inward inclination of 46 degrees, the 
mean direction being N. 44° E.; while on the left side of the 
track the mean inclination is not only inward but 48 degrees 
backward, the mean direction on this side being S. 48° W. We 
have thus a mean difference in the inclination of the fallen trees, 
on the two exterior portions of the track, of no less than 92 degrees. 
These indications seem conclusive, also, in favor of the whirl- 
ing action in the direction from right to left. 
10. Although of less importance, it should be mentioned that 
the diminished action of the tornado which is commonly ob- 
served on the hillsides and summits over which it passes, and the 
greatly increased action in the bottoms of the valleys, and even 
in deep ravines, afford a strong argument against ascribing the 
effects to the ascent of a non-whirling rarefied column ; as the 
latter, it would seem, must act with greater force on the hillsides 
and summits than in the bottoms of valleys. The general cor- 
rectness of the observation above stated cannot justly be ques- 
tioned. 
* The inclinations of the fallen trees from the course, on both sides the axis, are 
reckoned inward and backward. 
