N E A R N E W U A R M N y , I N D I A N A . / 



spiral revolutions from a to/,cqiKil areas in equal times ; if tlic whirl was stationary, 

 its force would he concentrically equal; but, if it have a constant progressive motion 

 in the direction of the axis c, c at J of the average rotative velocity, the force of 

 the whirl will be increased on the right, and diminished on the left side, of the axis. 

 Suppose the stationary velocity to be 80, then taking two equally distant points on 

 each side of the axis, the force will be increased to 100 on the right side, and 

 diminished to GO on the left when the cylinder is advancing. The consequence of 

 the rotative motion coinciding with the progressive is, that the prostrating power 

 extends much further on the right of the axis than on the left, where, from the 

 rotative being retarded by the progressive motion, the extent of the prostrating 

 power is lessened." " With these views," continues Mr. Redfield, " follow the track 

 of a tornado; and if it is a whirlwind, the result is a series of prostrations, pointing 

 almost invariably onward and inward, with various degrees of inclination to the 

 course of the tornado on one side ; while the left of the axis presents a narrow 

 band or belt of prostrations, also inclined mainly inward and onward, but showing 

 a greater inclination from the line of progress, with frequent cases more or less 

 backward, and sometimes outward, from the path." 



Now the prostrating effect of this rotating cylinder will be best understood b}' a 

 reference to the prostrated trees in Fig. 5, which correspond with the direction of 

 the involuted lines in the whirl. Making allowance for a little more onward direc- 

 tion, owing to the progressive motion, we may deduce the following general conclu- 

 sions : that on the right of the axis there cannot be any prostrations of trees with 

 their tops to the west;^ that those prostrated to the east cannot lie at a greater angle 

 with the direction of the track than 45°, unless they be very near the axis; on the 

 left of the track there cannot be any prostrations with the tops of the trees to the 

 east, except near the axis; and in the case of crossed trees, those on the right of 

 the axis, x^rostrated by the advanced portion of the whirl, will be undermost with 

 a N. E. direction; and those thrown down by the rear, will have a S. E. direction, 

 and overlie the northeasterly prostrations ; on the left of the axis, the S. W. pros- 

 trations will lie over the northwesterly. 



Apply these general principles to the square mile plot of the track at New Har- 

 mony, in Fig. 2, and observe if the conditions of the rotatory hypothesis are fulfilled. 

 On the contrary, there are numerous prostrated trees with the tops to the west on 

 the right of the axis ; many southeasterly and northeasterly prostrations, making a 

 greater angle than 45° with the direction of the course ; there are also many north- 

 easterly lying over southeasterly prostrations, as the groups of crossed trees show 

 where numbered, the lowest numbered being the first prostrated, or undermost tree ; 

 the same opposition to the rotatory hypothesis exists on the left of the axis, as may 

 be observed. 



Turn now to Fig. 6 of the map, which is an illustration of the bottom of an up- 

 moving column of air with horizontal conflux from surrounding space to the moving 

 centre. Let o be the centre, and a o, h o, c o, &c., represent the horizontal conflux; 

 the action of this moving column, according to Espy, will be to prostrate the trees, as 



' It must be recollected tbat in the drawing the top of the map is north. 



