1849.] Seventeenth Memoir on the Law of Storms. 277 



\Oth July. — Moderating from the S. E. to noon, when in Lat. 19° 17' N. : 

 Long. 124° 40'. The True Briton's Bar. 29.50 ; Ther. 85. 



Remarks. 



We have now, from the position of the two divisions, first to settle, as 

 before, that they successively had the same Cyclone, and then to as- 

 certain its track. 



We find that the first Division, on the 7th July at Noon, when in 

 Lat. 17° 21,' Long. 126° 20/ had the wind at N. E. b. N. a moderate 

 breeze increasing at midnight to a hurricane at N. N. E., and on this 

 day at Noon the bearing and distance of the second division from it 

 was N. 25° W. 157 miles. At midnight 7th, — 8th, the second division 

 had stood on about 30 miles to the S. Eastward, so as to make its dis- 

 tance at this time about 130 miles from the first division, which was 

 lying to. The breeze was freshening at midnight with flying squalls 

 and rain and a heavy sea, and the ships were reefing and (warned by the 

 preceding Tyfoon) striking topgallant yards and masts. We may take it 

 then, that they were not far from the outer verge of the Cyclone, which 

 at this time bore about S. E. from them (wind N. E). It should be 

 noticed that they continued to stand to the S. E. about 30 or 40 miles 

 more before heaving to. At noon of the 8th, the first division had it blow- 

 ing a hurricane, and they had their calm centre and subsequent shift of 

 wind at about 0.30 p.m. We may thus take the position given for the fleet 

 to have been also that of the centre, and it was in 17° 6' N. ; 126° 9' E. 

 At this time the 2nd Division bore from it N. 21° West 99 miles by its 

 position, and had the wind at between E. b. N. and E. N. E. increasing 

 so rapidly that at 2\ p. m. they hove to. The True Briton's Barometer 

 had fallen 0.18, but as it is only registered from Noon to Noon we cannot 

 base any calculation upon it. If we take the true average of the wind 

 to have been E. b. N. -J- N. this will give us the centre of the Cyclone 

 as bearing S. b. E. J E. (S. 16°E.) and we have seen that by the esti- 

 mated position of the two divisions (and that of the first division was of 

 course merely an estimate and nothing more,) it bore S. 21° E, and if 

 we take the distance to be 100 miles, the Cyclone was one of 200 miles 

 only in diameter. 



There can be no sort of doubt then that the two divisions experienced 

 again the same Cyclone, which passed over the first division, and to the 

 Southward of the second. Its track we may best deduce from the 



