24t Mr. W. C. Redfield on the Tornado 'wliich visited 



dered, will be limited to a shorter distance than on the op- 

 posite or progressive side of its axis. 



This is seen in the more limited extent of the prostrations 

 on the north or left margin of the track, as compared with 

 the extent of those which incline inward on the right side of 

 the apparent axis. — There were many trees standing beyond 

 the northern border of the track, but none had fallen. 



8. It follows, in like manner, that on that side of a whirl- 

 wind in which the rotary motion coincides with the pro- 

 gressive movement, the prostrating power will not only be in- 

 creased in its intensity, but will also be effective over a wider 

 space; and that few, if any, of the prostrated bodies will be 

 found to have been thrown backward. 



In the case before us, as may be seen in the sketch, the 

 prostrations are found to extend on the southern or right 

 side of the apparent axis to a distance nearly twice as great 

 as on the left side. The same general result has also been 

 noticed in the tracks of other tornadoes which I have ex- 

 amined. 



The facts here considered are too important to be ovei- 

 looked, and seem fully to establish the course of rotation. 



9. If a rotative action be exhibited, the mean directions of 

 all the prostrations, on each of the two opposite sides, will 

 differ greatly in their respective inclinations to the line of pro- 

 gress, 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 pro- 

 strations on the right side of the track is found to incline 

 fifty-seven degrees inward fiom 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 direction is found to be S. 6° W., 

 or ninety-six degrees inward and backward ; a difference in 

 the mean inclination from the course on the two sides of 

 forty-seven degrees*. 



If we now take the indications afforded by the two ex- 

 terior portions of the track, to the width of five chains on 

 each side, where the effects are more distinctive in their cha- 

 racter, we find on the right side a mean inward inclination of 

 forty-nine degrees; the mean direction being N. 41° E. : 

 while on the left side of the track the mean inclination is not 

 only inward, but fbrty-seven degrees backward; the mean 



* The inclinations of the fallen trees from the course, on both sides the 

 axis, arc reckoned in\\ard and backward. 



I 



