IN EUROPE DURING OCTOBER, NOVEMBER, AND DECEMBER 1863. 197 



17th December. These different depressions, however, soon reunited, and the 

 storm proceeded as before. 



Direction in ivliicJi the Major Axis of the Storm Area lay. 



The direction in which the major axis of the storm lay, could be determined 

 on twenty-eight occasions. On seven occasions it pointed to the N.E. ; on six to 

 the E. ; on five to the N.N.E. ; on four to the S.E. ; on three to the E.N.E. ; and 

 on three to the N. In most cases the major axis was coincident, or nearly coinci- 

 dent, with the direction in which the storm happened to be moving at the time. 

 These two features of storms have important bearings on the prediction of storms, 

 and on the direction and veering of the wind. 



It has been sometimes affirmed of the European storms that they are 

 constantly marked by a barometric depression stretching in a north and south 

 direction over Europe ; but the analyses of these storms given above show that 

 this assertion, in these cases at least, receives no support from fact. 



Direction in which the Storms advanced over Europe. 



The direction in which the storms advanced from the position they occupied 

 on one day to the position they occupied on the next day, could be ascertained 

 in twenty-four cases. In eleven of these, the progressive movement was to the 

 N.E. ; in four to the E. ; in four to the S.E. ; in two to the E.S.E. ; and one to 

 the E.N.E., S.S.E., and S.W. Thus, twenty-two travelled towards some point 

 in the quadrant from N.E. to S.E., and only one took a westerly direction. 

 Hence, these storms travelled as often toward the N.E. as toward all other points 

 of the compass put together, and almost every one toward some point between 

 N.E. and S.E. 



The storms seldom proceeded in the same uniform direction from day to 

 day. Though generally the change was not great, yet occasionally it was so. 

 Thus of the many interesting features which marked the storm of the beginning 

 of December, none were more remarkable than the sudden changes of its progres- 

 sive movement. I have added in the Appendix observations relative to this 

 storm at shorter intervals of time than 24 hours. From these it appears that the 

 centre of the storm on the 2d was near Liverpool at 9 a.m. (Plate XX.) ; Worcester 

 at noon ; Oxford at 3 p.m. ; Cherbourg at 6 p.m. ; and Oxford at 9 p.m. The greater 

 number of observations at 9 p.m. show three depressions : — 1st, at Shetland, 

 28-88 ; 2d, at Oxford, 28*89 ; and, M, in Holland, 29-22. It is very probable that 

 the storm had separated into two parts near Liverpool, one of which took a north- 

 easterly course toward Shetland, and the other a south-easterly course toward 

 Cherbourg. At 9 a.m. of the following morning (Plate XX.), the first had advanced 

 to the N.E. to Christiansund ; the second had advanced northward to Shields ; and 

 the third had advanced eastward to Denmark. At 9 p.m. of the 3d, the first was 



