1849.] Seventeenth Memoir on the Law of Storms. 259 



At this last time therefore the centre must apparently have been to the 

 N. E. b. E. of her, either inland or upon the coast of Luzon, (taking 

 it to have been only 80 miles in diameter in the last case,) and as from 

 midnight to daylight when it fell calm, the vessel was lying too, she had 

 not made much distance to the Southward. Capt. Shire's Chart places 

 her about this time in Lat. 16° 55'; Long. 119° 35'; and the shift 

 here was from N. W. b. N. to the S. W. This would show a track 

 off the land, but I learn from Capt. Shire that it drew to N. N. "W. 

 and West before it sprung up at S. W. veering to South by Noon, when 

 the vessel had run 69 miles to the Northward, as she had reached 

 18°04 North. 



It would seem then, that at this time, or from midnight to nearly 

 Noon, the Cyclone had either been forming or descending* about the 

 ship's position, or it may, not improbably, have been forcing its way over 

 the high land of Luconia, and this, whether formed upon the land, or as is 

 also probable coming in from the Northern Pacific, as the Cyclones of the 

 Bay of Bengal cross the Peninsula of India and descend on the Arabian 

 Ocean. I have sufficiently remarked in other placesf on the irregulari- 

 ties which may and do take place in the wind circles when a Cyclone 

 is in the neighbourhood of high land, so that I do not deem it necessary 

 to repeat these observations here to shew that we cannot from the mere 

 direction of the wind when so close in with the coast, ascertain correctly 

 the bearing of the centre, especially when, as in this case, the body of 

 the Cyclone is partly or wholly upon the land. 



I take then the place of the centre at this time only, viz. daylight on 

 the 18th, as the first positively well defined position for it, and we find 

 that from this time to Noon of the 19th, she was scudding before it 

 until compelled to heave to with the wind due South, blowing a Tyfoon ; 

 the vessel alternately heaving or broaching to, or bearing up to scud, as 

 her distress allowed, nor did this vary till midnight of the 21st, when it 

 fell calm. 



* " Forming or descending." My present theory is, (see Sailor's Horn Book,) 

 that Cyclones are rarely if ever found at the surface of the earth, but in the atmos- 

 phere above, and that they descend in disk-like whirls to the surface of the land or 

 ocean. 



f See Memoirs and Sailor's Horn Book, p. 70. 



