Mr. Redfield's Reply to Dr, Hare. 309 



rested, were so impelled by the wind as to make furrows in the 

 ground, of which one was nearly at right angles to the other. 

 Evidently such furrows could not rise from the transient tangen- 

 tial impulse of a whirlwind." pp. 144, 145. [22.] 



In the English Journal, Dr. Hare alleges that one of the four 

 posts on which the building was supported, ^'- was first moved to- 

 wards the tornado, as it advanced :" while Prof. Bache shows us 

 that the tornado advanced from south 80° west, to north 80° 

 east; and that the posts were first moved "to the west of north?'' 



But on what grounds this "fact" is pronounced "irreconcilable 

 with a general whirling motion," I am wholly unable to perceive. 

 For, had he closely examined the whole case, he would hardly 

 have failed to see that the movements of this building, as describ- 

 ed by Prof Bache, are fully "reconcilable" to an involute "whirl- 

 ing motion," such as I allege to be characteristic of these torna- 

 does ; and that there was no necessity for resorting to the gratui- 

 tous hypothesis of its being " protected by another edifice in one 

 direction," or even that of "the suction of the tornado." 



If a whirlwind figure having a diameter of three or four hun- 

 dred yards by the scale of Prof Bache's figure, [Plate III, fig. 3,]* 

 be drawn on tracing paper, with involute whirling lines repre- 

 senting, horizontally, the course of the wind from the exterior to 

 the interior of the tornado, and if the center or axis of this figure 

 be passed from west to east along the line pursued by the axis of 

 the tornado as indicated on the plate, revolving at the same time 

 to the left with a velocity greatly exceeding its advancing motion, 

 it may be seen that the wind of the whirl will be indicated as 

 beginning at this building from nearly south, i. e. moving " to the 

 west of north," nearly, or in the general direction of the first 

 furrows in the ground. It will also be seen, that the wind of 

 the whirl, changing by southwest, and having its gyrations 

 quickened near the center, would, immediately after the pass- 

 ing of its axis, exhibit its greatest force from the western quar- 

 ter, corresponding to the second movement of the posts in the 

 groimd ; the wind veering from thence towards the northwest as 

 the tornado passed away : thus showing two directions of wind 

 which sufficiently coincide with the first movements of the posts 

 of the building " to the west of north," and subsequently " to the 



* See Jour, of Franklin Institute, Vol. Ill, third series, 1841, pp. 273 and 276. 



