18 Fifth Memoir on the Law of Storms. [No. 121. 



and certainly not to be compared to the exactness derived from that 

 for the Madras ships and shift of wind on this day. I have however 

 marked her position for the 16th and 17th on the chart. 



The Barque Amelia from Vizagapatam to Madras had heavy gales 

 varying from ENE. to NE. on the 16th in lat. 14° 51' N. ; no longitude, 

 given ; but she was not very far from the coast, and thus shows clearly 

 enough that the storm extended to about the distance we have taken 

 As usual she had SE. winds on the following day. 



We have two very good stations for this storm, from which we are 

 enabled, I think, to fix its track and rate of travelling with tolerable ac- 

 curacy. The first of them is on the 15th, when we have the French 

 ship Petite Suzanne's log and that of the Hydroose, which give a centre 

 at noon on that day about where I have placed it, or in lat. 9° 52' N. 

 long. 87° 12' E. We have then Captain Biden's careful account giving 

 the shift of wind at Madras at 8. p. m. on the 16th. Now from noon on 

 the 15th to 8 p. m. on the 16th is 32 hours, and the distance is about 453 

 miles in that time, or 340 miles in the 24h. or 14 -'th per hour. Tak- 

 ing eight hours of this rate, or 113 miles, backwards from Madras on the 

 ESE. and WNW. line of its track, (it will be seen by Captain Biden's 

 letter that at Madras this was its track the shift being from NNE. to 

 SSW,) we have for noon of the 16th the spot I have marked, 113 miles 

 ESE. of Madras ; and as we find by the various logs of the vessels which 

 slipped from Madras roads, that the shifts or veerings of the wind were 

 between noon and 5 p. m., as they had necessarily run out towards it to 

 get the best offing they could, we cannot be far wrong. This centre of 

 the 16th agrees very remarkably with the log of the Hydroose, which 

 vessel had her shift of wind on its track, and if our rate is correct, about 

 10 hours before noon, or at 2 a. m. of the 16th. It will also, with al- 

 lowance for the drift (for her track was not the strait line it is laid 

 on the chart) agree very well with the position of the Petite Suzanne, 

 which vessel, by the rapid veering of the wind, must have had the centre 

 not far from her at one time ; and I attribute to this the anomaly of her 

 having had the wind for about three hours from NE. to East. It will 

 be borne in mind, in considering the two positions of this vessel, that 

 there is good reason to suppose that in these storms strong partial ma- 

 rine currents may be at times created.* We may also remark of hert, hat 

 * Col. Iteid, and various logs in ray preceding Memoirs. 



