l54 On ifie 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 directioa 

 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 rafters 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, I am 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 

 elcGtricity 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. 



The 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 



