50 Mr. Redfield on the Rotary Action 
siderations:—1. The ascertained existence of a stratum of un- 
usually cold air in the higher region of clouds, on some parti- 
cular days remarkable for the occurrence of numerous thunder 
gusts and tornadoes*. 2. The observed descent of a portion 
of the clouds in front of the nucleus or body of a heavy squall 
or tornado, which may sometimes be traced by the eye as low 
as the existing limit of condensation will afford opportunity 
for observation. 3. The fact noticed by Mr. Allen and others, 
that adjacent “to the exterior edge of the circle of the tor- 
nado” or whirlwind, the previous breeze often continues * to 
blow uninterruptedly from the same quarter” as beforet. 
4, The last fact, when taken also in connexion with certain 
peculiar and striking effects in the outward portions or edge 
of the tornado, a knowledge of which I have gathered from 
various sources. 5. The coldness of the air which has been 
noticed at the edge of awhirlwind. 6. The instant penetration 
of the lower end of the whirlwind into thick forests, and into 
hollows and ravines, which has been frequently noticed. 
7. The direct memorials of downward action in the outward 
portions of the whirl which I have myself met with on the 
tracks of different tornadoes. 
In most of the foregoing remarks it has been my design to 
view the tornado as it moves onward, in full action. Of the 
origin or incipient causes of the whirl, it is not necessary here 
to inquire; although some clue to these is perhaps afforded us 
in the considerations above noticed. 
Recurring once more to the track of the Providence tor- 
nado, I have to state that eastward of Tifts’ house the course 
of the track soon became 8. 65° E. magnetic, for more than 
two miles. It then took the course of S. 75° E., and further: 
onward the tornado passed directly over the house of Solomon 
Peck, about four miles from Providence. This house was 
partly unroofed ; chimney thrown down; windows broken 
inward, as in many other cases; and much other damage was 
also done to Mr. Peck’s property. In passing onward towards 
* This change of upper temperature I think can be clearly made out on 
the day of the New Brunswick tornado, which was but one of many terna- 
does and thunder gusts which appeared in this part of the United States on 
the same day; and on the preceding day in Illinois and other western 
states. 
In the New Haven Gazette are accounts of five severe tornadoes which 
occurred inthe states of New Jersey, Connecticut, Massachusetts and Rhode 
Island, on the afternoon of August 15,1787. Icanalse refer tomany more 
recent cases of this kind. 
+ ‘The observation here quoted is one cf many which show the error of 
the very hasty generalization which alleges a circuit or annulus of calm air 
to have been observed on all sides of tornadoes and hurricanes, 
