1850.] Nineteenth Memoir on the Law of Storms. 381 



Log more closely so as clearly to set forth the reasons on which this 

 opinion is founded. We shall find moreover that the JBraemar's 

 Cyclone was a separate one from those of the Jumna and Sultany. 



First: we have her position at 3 a. m. of the 23rd as marked on 

 the chart when it "came on to blow." The wind is marked at N. W. 

 in the Log* and "West at 5 a. m. though the copy of Lieut. Rodney's 

 Admiralty letter forwarded to me by H. E. the Naval Commander-in- 

 Chief, says " a heavy gale sprung up at North, veering at times to 

 N. N. W." This is, at starting, a troublesome discrepancy, but I 

 reconcile it by supposing that North West was written at full length 

 in the letter and the word West omitted by the copying clerks ; for it 

 is difficult to suppose that three copies of the Log by different hands 

 are all in error. The wind is also marked N. W. from 9 p. m. to 

 midnight on the 22nd. The Barometer at 29.64 at midnight 22nd and 

 29.57 at 3 a. m. 23rd; and the wind increasing from a force of 5 to 

 7 and 8.f 



Hence we may say that the Jumna had a sudden onset of a fresh 

 gale, at N. W., giving her a centre bearing S. W. of her at 3 a. m. ; 

 which by 5, when she had run 27 miles to the South and S. S. W., was 

 bearing South of her (wind West) and in a run of 14-4 miles it was 

 bearing S. S. W. of her, (wind W. N. W.) and in a run of 43 miles 

 more, it was bearing W. S. W. of her, (wind N. N. W.) 



We can only account for these excessive veerings by attributing them 

 either to incurvings of the winds or to the action of a smaller Cyclone^ 

 travelling down with the ship, I prefer the latter hypothesis, and have 

 therefore placed upon the chart a separate diagram upon a plane scale 

 shewing the Jumna's run, and the various bearings of the Cyclone 

 centre from her at different hours, with the height of her Barometer. 



* Three copies in all. 



f Admiral Beaufort's Numbers. 5 is a fresh breeze, 8 a fresh gale. 



% Of which we may suppose the centre to have had that spiral motion upon 

 itself during its progress described by Mr. Redfield, making thus the meandering 

 track which I have laid down in the diagram ; and even that these deviations from a 

 direct line of track were occasioned by the alternate attractions and repulsions of 

 the larger (Sultany's and Braemar's) Cyclones on each side of it, as with other 

 electrified masses. It is evident that the three cannot be reconciled as one Cyclone 

 till about the time of the Jumna's being dismasted. There is indeed one other, 

 but a remote suspicion : namely, that her compasses may have been affected ? 



3 D 



