380 Nineteenth Memoir on the Law of Storms. [No. 5. 



Jumna s Cyclones met that the latter vessel was upset, or that there 

 were some excessive incurvings of the winds with her at this distance 

 from the centre.* 



For we find by the Jumna! s Log that she had the usual fine and 

 squally weather up to 3 a. m. on the 23rd, when it came on to blow 

 from the N. West ; and at 5, veered to West ; at 6, to W. N. W. ; and 

 at \ past 8, to Noon it was N. N. W. and p. m. N. b. W. 



Now the Sultany before, and up to Noon, had her Cyclone to the 

 N. W. of her position, and though it is true that a storm circle which 

 would include the Braemar and Mary Stoddart, both of which ships 

 had a full hurricane on the 23rd, would also include the Jumna's posi- 

 tion and run, yet it is difficult to allow so great a discrepancy in the 

 position of the centre as denoted by the wind points shewn above ; 

 and this is farther strengthened by the fact that the winds on board 

 the Jumna, though marked most carefully (nine times in the 24 hours 

 on the 22nd, and twelve times in the Log of the 23rd), are never to the 

 Eastward of North ; which we certainly must suppose they would 

 sometimes have been if the bearing of the centre had been so far to 

 the North Westward of the Jumna as the Sultany s position, whether 

 over or under-stated, shews. We may also remark that even at the 

 calm centre and close upon it the Jumna's Log shews only vibrations 

 of two points till the wind finally settled at S. W. after the shift. 



Thus we are reduced to the first supposition, which is that the 

 Jumna was bringing down with her another small Cyclone, and if we 

 admit this, and that it was for a time travelling on a track gradually 

 approaching her as shewn by the steady fall of her Barometer, we can 

 easily understand that at the point where the two approximated and 

 combined, the fury of the tempest might be much augmented and the 

 track subject to some variation. f I proceed to examine the Jumna's 



* Five points is not an excessive incurving of the wind when near the centre, 

 but at this distance it would seem to be so. See Sailor's Horn Book, pp. 70 to 75, 

 on the incurving of winds. The wind was of course accurately marked on board of 

 the Man-of-War, and I do not recollect that we have any detailed Log of a Man- 

 of-War in recent days in the Eastern Seas in an open Ocean. Those of H. M. S. 

 in the China Seas cited in my Seventeenth Memoir are all within a short distance of 

 the land. 



f This certainly occurs with hail storms, as satisfactorily shewn by the Count de 

 Tristan in the Annales de la Societe Roy ale d Orleans. See Quarterly Journal of 

 Science for 1829, p. 214. 



