154 On the Causes of the Tornado, or Water Spout. 
trees or houses for instance. On these accounts, neighboring trees, 
falling at different times, had different bearings; but that they all fell 
towards the point occupied by the axis of the tornado at the time of 
their overthrow, appears to be consistent with the facts. In one in- 
stance, both Prof. Bache and Mr. Espy observed that the post of a 
frame building, being dislodged from the stone on which it rested, 
was first moved towards the path of the tornado in one direction 
about eighteen inches, marking its course by a furrow in the ground, 
and afterwards moved in another direction, nearly at right angles to 
the former, leaving a similar indication of the course in which it had 
moved. Intermediately between the time when the tornado bore in 
those directions, the frame was protected by a house. 
. While the phenomena above described sufficiently indicate the ex- 
istence of a horizontal conflux of the air, that of a vertical force was 
demonstrated by the transportation of the debris of the houses and 
trees, as well as lighter bodies, to a great distance. A lady’s reticule 
was carried seven miles from New Brunswick, and a letter twenty 
miles. The piece of timber, technically called the plate, on which 
the rafiers of the roof of a church in New Brunswick rested, was 
carried nearly a quarter of a mile, and lodged in some trees beyond 
the Raritan. The fields, on the other side of that river, were strewed 
with shingles torn from the houses in the town. 
After maturely considering all the facts, Iam led to suggest that a 
tornado is the effect of an electrified current of air, superseding the 
more usual means of discharge between the earth and clouds in those 
sparks or flashes which are called lightning. I conceive that the in- 
evitable effect of such a current would be to counteract within its 
sphere the pressure of the atmosphere, and thus enable this fluid, in 
obedience to its elasticity, to rush into the rarer medium above. 
It will, I believe, be admitted, that whenever there is sufficient 
electricity generated to afford a succession of sparks, the quantity 
must be sufficient, under favorable circumstances, to be productive 
of an electrical current ; and that light bodies, lying upon one of the 
electrified surfaces, may be attracted more or less by the other. 
e phenomena of the rise and fall of electrified pith balls, called 
electrical hail, sufficiently justify this last mentioned statement ; while 
the continuous stream is illustrated by the electrical brush, or the 
blast of air produced by a highly electrified point. 
_ It will also be conceded, that thunder and lightning are caused by 
discharges of electricity between the earth and clouds, analogous to 
