é 
Is 
‘- - Vol. xxxvin1, No. 2.—Jan.-March, 1840. 
Miscellanies, AD1 
Peltier, after due investigation, came to the conclusion that a torna- 
do is a modification of the thunder gust, in which, in lieu of passing 
in the form of lightning, electricity passes through a cloud, acting as 
a conductor between the terrestrial surface and the sky. It will be per- 
ceived that this view of the subject differs but little from that which, in 
amemoir in the transactions of the Society, had been presented by 
Dr. Hare, in the following language :—“ A tornado is the effect of an 
electrified blast of air, superseding the more usual means of discharge 
between the earth and clouds, in the sparks and flashes which we call 
lightning. I conceive that the effect of such a current would be to 
counteract, within its sphere, the pressure of the atmosphere and thus 
to enable this fluid, in obedience to its elasticity, to rush into the rarer 
medium above.” 
Dr. Hare went on to say, that the only difference arises from the 
omission of the Parisian philosopher to call in the elasticity of the air 
in aid of the electrical forces, and his assigning to a cloud the agency 
which Dr. Hare had attributed to a vertical blast of electrified air, min- 
gled with every species of movable matter coming within the grasp 
of the meteor; and that it would seem, from a subsequent communica- 
tion made by Peltier to the Institute, that he had so entirely misappre- 
hended Dr. Hare’s theory, as to ascribe to it deficiencies for which it 
Was not amenable, but which had existed in his own explanation, as 
stated in his report. 
The fault of Dr. Hare’s explanation was, according to him, “en 
ne tenant pas compte des forces nouvelles que la premiére, (that is 
to say, the electric attraction,) acguiert par le mouvement gyratoire 
a " ? Ip ? 
qui accompagne souvent la coulonne de nuages et deau qu’on appelle 
trombe.” 
As the most appropriate refutation of this misstatement, Dr. Hare 
stated that he would quote a paragraph from his Memoir. 
‘© When once a vertical current is established, and a vortex pro- 
duced, I conceive that it may continue after the exciting cause may 
have ceased. : 
“ The effect of a vortex in protecting a space about which it is 
formed, from the pressure of the fluid in which tt has been induced, 
must be familiar to every observer. In fact, Franklin ascribed the 
water spout to a whirlwin 
om , 
* Tout confirme donc que la trombe n'est qu’un conducteur ne elle sort 
@ Dass. Sk j lle d i t 
» | + 
L=—3 ‘3 - 
ge accompagné du trombe, est dans ce con 
ot ee Ve Genenhin ot ft rH A 1 
servant a 
q 
pre Pt 
Z DB =] 
Orage ordinaire et l’ora 
établir le combat entre ; t : 
(See Peltier’s report upon the tornado of Chatenay, Journal des Debats du 17 Ju- 
ilet, 1839 
51 
