376 Twelfth Memoir on the Law of Storms in India. [No. 161. 



of this new vortex, which seems I think to be evidently one thrown 

 off from the great one, of which the centre as we have placed it for this 

 day was now at ninety miles to the SW. of the Fattel Hair, and we 

 cannot be very far wrong in her position or in its place also. If she had 

 had any part of the great storm, she must have had a steady gale from 

 the «S. Eastward. 



This is an instance then of a smaller and less intense vortex follow- 

 ing, or being thrown off from, a large one, and it was certainly much 

 smaller, for we find that with the wind North at Noon on the 10th, 

 the Fattel Hair had it at a little past midnight at SW. or it had veer- 

 ed 12 points in, say, 13 hours, and was then moderating. I have 

 thus marked it as a small circle, only to shew its independence of the 

 main storm. I need not add that it had no connection with the 

 Royal Sovereign's storms. 



We have no farther data for tracing this storm within the Islands, 

 and we have now to consider if it could have been the storm which 

 dismasted the Petite Nancy. 



I think decidedly not. We see that, presuming that it was travel- 

 ling on from the 10th, and not breaking up of itself there, it must, 

 to have reached the Petite Nancy, on the I lth first, have run faster 

 than the Fattel Hair, which it did, since it left her with the winds 

 from SW. at midnight 10th- 11th, to SSE. at noon of the 11th, and 

 then have overtaken the Dido again with another storm, from NE. or 

 N W. striking her with its Western quadrants. The Dido had her second 

 storm only on the \5thfrom the SE. and SW. so that she was skirting 

 the Eastern edge of a storm already to the Westward of her. All 

 this makes it probable that the Petite Nancy's storm was rather, 

 if not a separate storm also, the Briton and Runnymede's, which 

 must have been upon the Great Andaman, on the 12th, and pro- 

 bably between that day, and the 14th, forced its way over the 

 mountain chains of that island, and travelled up or re-formed itself 

 in the Bay.* The winds which the Petite Nancy had on the 12th 

 when she was at 90 miles only from the body of the Great An- 

 daman, and but a little to the Northward of the wrecked ships, were 



* For an example of a storm forcing its way over high land and re-forming again, 

 see Journal, Vol. XII. Eighth Memoir. 



