9Q6 Fourteenth Memoir on the Law of Storms in India. [No. 168. 



remaining seventy miles in ten hours, allowing a little for the storm wave ? 

 the total rate of her run would then be 160 miles in twenty-two hours, 

 or say, 7.3 miles per hour, or 1.4 miles faster than the vortex was mov- 

 ing before her. 



If we assume the hurricane to have moved at this rate above men- 

 tioned, 5.9 miles per hour, it follows that the ship in the twenty- two 

 hours that she was chasing it, only gained upon it at this rate of 1.4 

 miles per hour, which would give her distance at noon on the 29th, 

 to have been really only thirty miles from the centre ! and yet with only 

 a double-reefed topsail breeze. 



This would give but sixty miles of diameter, but though we have had, 

 it is true, instances of hurricanes which like this have not much exceeded, 

 as far as we could judge, sixty miles in diameter, yet I am inclined 

 to allow it somewhat more than this, and we must therefore suppose, 

 either that it was not completely formed at noon of the 29th, though the 

 Caledonia's barometer (29*70) would indicate that it was enough so to 

 produce the usual barometric depression, or that it was at a greater dis- 

 tance and moving at a slower rate. 



We have no sort of indication to guide us in this estimate, so that 

 I have, as a mere matter of choice and probability, placed the centre this 

 day at fifty miles WbS. from the Caledonia's position, which gives it 100 

 miles of diameter. It could not have been much more, for we shall see 

 that on the 30th, when she was within the calm centre, the John Wickliffe, 

 at eighty-two miles to the SbE. of her, was barely experiencing the 

 remote effects of the swell, in pitching away her flying jib-boom, while 

 her wind, though Westerly, was declining to calm. The John Wickliffe, 

 as she ran up, must have crossed, at about 8 a. m., on the 1st, the 

 place of the centre a little before noon of the 30th. We find that the 

 heavy head sea is again noted, p. m., but not at midnight, perhaps this 

 is an omission in copying, or of a careless officer ? It would have been 

 of interest to have found traces of the confused sea of the centre at the 

 very place of it, as we have done in other instances. 



The storm had not formed and moved onward at the same rate on 

 the 28th, for then, as will be seen by measuring backwards on the chart, 

 the Alibi would have had very different weather. We shall find in 

 our examination of the Hindoostan's log for the day in which she 

 steamed through the hurricane, that its diameter then (on the 1st and 



