274 Seventeenth Memoir on the Law of Storms. [March, 



the gale was at its highest and it would be difficult to conceive a more furious 

 one while it lasted ; the Marine Barometer being rather below 29.1 at that time, 

 which was its greatest fall; towards Noon the squalls slackened, though we had 

 hard rain and very thick weather." 



We have first to consider if the Cyclones of the first and second 

 divisions of the Fleet were one and the same, and for this we must 

 first consider their distance apart. 



It appears that the 1st Division was on the 1st of July at Noon in 

 the Western edge of its Cyclone, the wind (North to N. N. W.) in Lat. 

 19° 10' North ; 124° 25' East', running to the S. Eastward till midnight 

 the wind increasing in strength and being then at S. W. The position 

 of the Division at this time was about 18° 03' N. ; Long. 125° 15' E. ; 

 and at the same time, midnight, 1st and 2nd, we find that the 2nd Divi- 

 sion was in Lat. 21° 21' ; Long. 122° 38', or at a bearing and distance 

 of N. 37' W. ; 250 miles from the 1st, with its Cyclone just commen- 

 cing at North. 



As the first Division had the wind at this time N. W., and was close 

 upon the centre, we may say that the centre of their Cyclone was in 

 about 18°20', N. 125° 30', E. or thereabouts, which will give the bearing 

 and distance between the Cyclone and the body of the 2nd Division as 

 S. 42° East about 244 miles, which we may take as being about the 

 semi-diameter of the Cyclone, making its diameter to be 488 miles, 

 which, for a Pacific Ocean one, is not at all excessive. 



If we look now at Captain Stanley Clarke's Barometer register, we find 

 that between Noon and 3 a. m. it is noted to have fallen 2-tenths, which 

 for the whole 15 hours would give a fall of 0.13 per hour, but it is 

 evident that this fall must at least have taken place after sunset, 

 since nothing is said about a falling Barometer at that time, when the 

 first reefs were taken in. Hence we may fairly assume that it was a 

 fall of at least 0.02 per hour,* which would give an approximate dis- 

 tance of say 250 miles at midnight. 



Now it appears from the logs of the second Division that the Cyclone 

 was, as we have seen, bearing at midnight about S. 42 East 244 miles 



* In the next Cyclone in the Log of the Buccleugh of the 8th the Barome- 

 ter is marked at Noon of the 7th at 29.27 and at Noon of the 8th, 28.55, and the 

 remarks say : — " The barometer fell very fast towards Noon." We should evidently 

 take an unfair average here if we assumed the fall to represent that of the 24 hours, 

 when it probably took place in 12, or even in six hours. 



