Dove on the Law of Storms. 319 



above the place of observation, it necessarily follows that the ab- 

 solute extremes of these variations must arise from the exclusive 

 prevalence of one of the two currents over the other. Thus a 

 barometric minimum would be a phenomenon of the south cur- 

 rent ; when viewed as occurring simultaneously at several places, 

 the south current itself; when viewed locally, a stormy passage 

 through the minimum of the wind circle ; or comprehending both 

 views, a whirl or whirlwind advancing in the direction of the 

 south current, i. e. from S. W. to N. E. In confirmation of this 

 view, I subjected the observations collected by Brande and oth- 

 ers to a new examination, and in a treatise, entitled ' On Baromet- 

 ric Minima,' which appeared in Poggendorff's ' Annals' in 1828, 

 Vol. xiu, p. 596, I pointed out, that a simple explanation of all the 

 phenomena could be afforded, on the assumption of one or more 

 great rotatory currents, or whirlwinds, advancing from S. W. to 

 N. E. ; and I remarked at the same time, that in all the hurri- 

 canes of the southern hemisphere which I had examined, the rota- 

 tory movement was in the opposite sense to that which took place 

 in the northern hemisphere. As the example discussed in that 

 paper contained a complete refutation of the idea of a flowing in 

 towards a centre, I will here repeat the principal quantitative de- 

 terminations. 



On the 24th December, 1821, at 6 p. m., the barometer stood 

 below its average height, as follows : — 22 lines at Brest ; 19 at 

 Helston and Nantes ; 17 at Gosport ; 16£ at Dieppe ; 15 in Lon- 

 don, Haarlem and Paris ; 11 at Strasburg, Geneva and Bremen ; 

 10 at Zurich, Gottingen and Bergen; 9 at Joyeuse and Augs- 

 burg ; 8J at Wurzburg ; 8 at ftegensburg and Leipsic ; 7 at 

 Prague, Breslau and Christiania ; 6J at Cracow, Apenrade and 

 Abo ; 5 at Turin and Modena ; 3£ at Florence ; 3 at Tilsit and 

 Petersburg ; 1£ at Rome ; 1 at Molfetta. 



On the 25th December, at 3 a. m. — 22 lines in London ; 21£ 

 at Dieppe ; 20 at Gosport and Boston ; 19 at Helston ; 18| at 

 Paris; 18 at Haarlem; 18£ at Kinfauns Castle; 16| at Stras- 

 burg; 15 at Heidelberg , 14 at Cologne, Regensburg and Got- 

 tingen ; 13 at Geneva, Zurich, Augsburg, Berlin and Bergen ; 

 12^ at Joyeuse ; 12 at Regensburg, Gotha and Leipsic; 11 at 

 Prague and Breslau ; 9 at Turin ; 8 at Milan and Cracow ; 7£ 

 at Christiania ; 6 at Abo ; 5 at Florence, Rome and Tilsit ; 3 at 

 Molfetta ; 2£ at Petersburg. 



