WTiirlwinds excited by Fires. 369 



millimetre, while in the Naudou, they are perhaps a little less 

 elongated ; for the mean of the measm-es we have taken has 

 given 7jth by isjd of a millimetre. 



With regard to the note of M. Mandl, it may be seen that 

 \VQ have found his observations exact and interesting, and we 

 accordingly propose to the Academy to view them favourably, 

 and to engage this physiologist to prosecute the researches, 

 an account of which we have now given. 



Some Account of Violent Columnar IVhirlwinds, which appear 



to have resulted from the action of large Circular Fires ; 



with Bemarks on the same.* By Mr W. C. Redfield. 



Since my attention was first attracted by the- phenomena 

 of our great whirlwind storms, I have found frequent occasions 

 for noticing the points of analogy, and also of dissimilarity, 

 between these great storms and the smaller classes of whirl- 

 winds which are known under the various names of squalls, 

 thunder-gusts, tornadoes, water-spouts, sand-pillars, and the 

 like. While pursuing this inquiry, I received information of 

 a few cases in which whirlwinds of great activity and violence, 

 appeared to have resulted from the action of fires. The facts 

 attending these cases, as then related to me, were carefully 

 noted, and were laid aside with a view, at a future period, to 

 incorporate them with a more general account and examina- 

 tion of the smaller description of whirlwinds, than I have yet 

 found it convenient to undertake. In the mean time, the ver- 

 bal statement of these cases, both in Europe and this country, 

 through the medium of a friend who is distinguished for his 

 attainments in science, appears to have exited some interest 

 in the minds of meteorologists and others, and has occasioned 

 applications to be made to me for a full statement of the facts. 

 I therefore hasten to give them publicity, without the delay 

 which the execution of my original purpose would necessarily 

 occasion. 



The most recent of these cases, being the first of which I 

 obtained notice, occurred in the year 1830, in the township of 



' Read before the Conn. Aciid. of Arts and Sc, Jan. 22. 1839 ; afterwards 

 published in vol. xxxvi. of Sillimau's Journal. 



