yV hirlwinds produced by the burning of a Cane-Brake. 185 
_ wind was continued notwithstanding the change in its direction. 
Some were bent into a direction nearly or quite horizontal still 
revolving rapidly, others were less inclined, and others were cut off 
on a level with the general mass of smoke or prolonged into the 
transparent air above 
* In connection with the whirlwinds several other facts of in- 
terest may be mentioned which occurred during the burning of 
the cane. me 8 
1. The direction of i wind was changed. Being at first 
_ from the northeast, it céfttinued.in that direction in the upper 
part of the atmosphere,.gs was evident from the way in which 
_ the columns of smoke were bent. But shortly after the com- 
mencement of the burning, the air beneath blew in all directions 
towards the center of thé fire. The columns of smoke rising 
hearly straight for more than two hundred yards, and being then 
quite suddenly bent, served to indicate accurately where the gen- 
eral northeast wind prevailed over the currents that surrounded 
the fire. The influence of the fire may therefore be considered 
as having extended more than two hundred yards* in height, and 
Over an area of more than three hundred yards around, for at this 
distance the air blew strongly towards the fire. 
- The entire influence of the fire appeared to be expended on — 
the air in its vicinity, and to produce no effect on the general 
state of the atmosphere, either at the time or subsequently. This 
fact is the more important as storms in the region where this fire 
Sccurred, particularly thunder storms, are much more frequent 
and violent than in the Northern States. 
he whole mass of the air, after entering the area above the 
fire, exhibited a tendency to rotary motion, being full of eddies 
and whirlwinds. 
These whirlwinds revolved on their axes from right to left, 
and from left to right, without any prevailing tendency to one 
direction more than to the other. Frequently the same whirl- 
wind would change the direction in which it revolved and would 
teturn to its first course. In a few instances this was repeated 
Several times. In no instance, however, was this repeated change 
of rotation observed in the whirlwinds of the form represented in 
No. 2, and from this it was evident that this change was owing 
toa change in the form of the base, as thé fire burned down the 
pile of cane on which the whirlwind was:formed. The nicely 
balanced columns of air ascending in the whirlwind would com- 
mo 
gy these columns except a few scattering trees in the fir 
_ Skeoxm Serres, Vol. XI, No. 32.—March, 1851. 
4 
ra: * Probably more than three hundred yards—there was no object with which to 
i c 
24 
