328 Proceedings of the British Association. 



however depended on the longitude than on the latitude of places. 

 The barometer was at its minimum at Cape Wrath, in the N. N. W. 

 corner of Scotland, two hours and a half sooner than at the Calf 

 of Man, five hours sooner than at Edinburgh, and thirteen hours 

 and a half sooner than at Thwaite, in Suifolk. Mr. Espy then 

 stated that he had examined the data furnished by Col. Reid, of 

 several hurricanes in the West Indies, and found conclusive evi- 

 dence that the wind blew inwards to a central space in all these 

 storms. Diagrams of two were exhibited : — one on the 3d of Oc- 

 tober, 1780, in which Savannah-la-Mar was destroyed. In that 

 storm, at its very height, the wind at Savannah-la-Mar, on the 

 south side of the island of Jamaica, was south, — and nearly oppo- 

 site to that point, on the north side of the island, the wind was 

 N. E., or nearly in an opposite direction, for two hours at the time 

 of the greatest violence of the storm at both places. The other 

 storm was on the 18th of August, 1837, ofl' Charleston, S. E. 

 On that day, the ship Duke of Manchester had the centre of the 

 storm pass over her, and on the same day, the West Indian and 

 the Rawlins, which were on the southwest of the Duke of Man- 

 chester, had the wind all day from 2 A. M. southwest, and at the 

 same time the Cicero and the Yolof on the N. E. of the Duke of 

 Manchester, had the wind N. E. and E. N. E. The Yolof all 

 day, till 8 P. M. Mr. Espy then stated that he had visited the 

 tracks of eighteen tornadoes, and examined several of them with 

 great care, and found that all the phenomena told one tale, — the 

 invA''ard motion of the air to the centre of the inverted cone of 

 cloud as it passed along the surface of the earth. From all these 

 facts he demonstrated that there is an inward motion of the air 

 towards the centre of storms from all sides ; and that this is the 

 inference which ought to be drawn from the well-known fact, 

 that the barometer stands lower in the midst of a storm than it 

 does all round its borders. The difficulty is, to account for the 

 continued depression of the barometer, notwithstanding the great 

 rush of air at the surface of the earth towards the place where the 

 barometer stands lowest. So great did this difficulty appear to 

 Sir J. Herschel that he stated to the British Association at New- 

 castle, that it appeared to him fatal to Mr. Espy's theory. It ap- 

 peared to Sir John that the only way to account for the fall of the 

 barometer was a centrifugal force in the air, arising from the 

 whirlwind character of storms. Mr. Espy thought it probable 



