104 British Association fo?' the Advancement of Science. 



uary, 1838, which committed such dreadful ravages in England. 

 A careful analysis of the information I have collected, leads me, 

 (said Mr. O.) to the opinion that this was a small, but violent rota- 

 tory storm, moving forward at the rate of 30 or 35 miles per hour. 

 The diameter of the rotating portion, I am not prepared to give, 

 nor do I consider it at all certain that it could be ascertained, as 

 it seems likely that the revolutions were not in contact with the 

 earth. The tendency of this eddy, or violent whirling of the air, 

 would of course, be to produce a vacuum in the centre. The air 

 that forms the eddy being constantly thrown off in a slight de- 

 gree spirally upwards, and dispersed on the upper portion of the 

 atmosphere, the effect of this would be, to produce a strong cur- 

 rent upwards. Now, supposing this large eddy to be perfectly 

 stationary, there would be a rapid rush of air towards it from all 

 sides, which would be drawn up and thrown off through this ro- 

 tating circle, and dispersed with amazing rapidity above ; but as 

 it is moving on with great velocity, the air that is in the advance 

 of the storm is not sensibly affected until the whirl is close upon 

 it, while in the rear the motion of the air is greatly increased ] 

 first, by the tendency of the air to rush into the great vortex of 

 the storm ; and secondly, by the motion onward of the vortex 

 itself. This vortex or revolving column would increase in size 

 upwards, so as somewhat to resemble a funnel ; it would, in fact, 

 be similar in its shape and action to an immense water-spout ; 

 whether it was vertical or not is entirely a matter Of conjecture, 

 but I should consider it probable that it would incline in the direc- 

 tion that the storm was moving, namely, to the N. E., and that 

 it was an upper current that carried it in that direction. The 

 greatest intensity of the storm in England was evidently across 

 Lancashire and Yorkshire. I therefore conceive that the nucleus 

 of the hurricane passed in a N. E. direction over these two coun- 

 ties. Towards the sides, however, a little current set in a S. and 

 even slightly in a S. E. direction, on the S. side of the vortex ; 

 and in a N. W. and W. direction on the N. side, as before stated ; 

 but the main rush is behind. Our anemometer shows that we first 

 felt a fresh S. wind with a slight bearing of E. in it, which very 

 shortly became more westerly, increasing considerably in vio- 

 lence. It then moved round to the S. W. and became quite a 

 hurricane, and continued so, very violent at first, but decreasing 

 in strength during the remainder of the day. At Plymouth it 



