Notices of Tornadoes^ ^c. 85 



gyration does take place occasionally, if not usually, since in the 

 case of liquids rushing into a vacuity, a whirlpool is very apt to 

 ensue. But as slight causes will in such cases either induce or 

 arrest the circular motion, such movements may be contingent. 

 It would however appear probable that when gyration does exist, 

 it may, by the consequent generation of a centrifugal force, tend 

 to promote or sustain the rarefaction and thus contribute to aug- 

 ment the force, or prolong the duration of a tornado. 



From observations made upon the track of the recent tornado 

 at New Haven, I am led to surmise that there was more than one 

 axis of gyration and vertical force. I conceive that in conse- 

 quence of the diversities in the nature of the bodies or the soil, 

 there was a more copious emission of electricity from some parts 

 of the rarefied area than others. In two instances wagons with 

 iron wheel tires and axles, were especially the objects of the rage 

 of the elements. Trees equally exposed were unequally affected, 

 some being carried aloft, while others were left standing. The 

 area of a tornado track may be more analogous to a rough surface 

 than a point, and the electricity may from its well known habi- 

 tudes, be given off only from such bodies as are from their shape 

 or nature most favorable to its evolution. 



Since these inferences were made, I have observed in Reid's 

 work upon storms, that similar impressions were created by facts 

 observed during a hurricane at Mauritius, in 1824. It was re- 

 marked that narrow, tall and decayed buildings, ready to tumble 

 into ruins, escaped at but little distance from new houses, which 

 were overturned or torn into pieces. It was inferred there were 

 local whirlwinds, subjecting some localities to greater violence 

 than others in the vicinity. In the case of other hurricanes sim- 

 ilar facts have been noticed. 



It may be expedient here to subjoin, that I consider a hurricane 

 as essentially a tornado, in which an electric discharge by " con- 

 vection^''^ associated with discharges in the form of lightning, takes 

 place from a comparatively much larger surface. In the case of 

 the hurricane, however, the area of the track is so much more 

 extensive, that the height of the vertical column to the diameter 

 of the base being proportionably less, there is necessarily a modi- 

 fication of the phenomena, which prevents the resemblance from 

 being perceived. In the case of the hurricane, the column is too 

 broad to come within the scope of a human eye. 



