690 A Sixth Memoir on the Law of Storms in India. [No. 127. 



N. W. with its centre close to her ; that of the Vansittart beginning 

 only at sunset on the 17th — the memorandum which I have exactly 

 copied evidently relating to civil time,* though it is not said so. 



The Vansittart' s second storm is, I think, also clearly a monsoon gale, 

 as there is no account of its veering or changing. I have therefore 

 marked her first storm, conjecturally only, parallel to our track No. V. 

 as passing Cape Bolinao, and travelling to the W. S. W. 



The singular phenomenon of the Barometer's giving no warning, 

 remaining so high, and falling so little in such a terrific tempest, is 

 most remarkable. Our first care is of course to ascertain, that it re- 

 ally occurred, before reasoning about it. I wrote to Captain Burt, who 

 was then Chief Officer of the Ariel, requesting to know if there was 

 any reason to mistrust the Barometer in any way ? if they had com- 

 pared it on arriving at Macao ? &c. His answer is as follows : — ■ 



" We had no reason to mistrust the Barometer, as it had always 

 indicated any change in the weather correctly. I am not aware whe- 

 ther Captain Warden compared it with any other in Singapore or 

 not; he was then in command of the Ariel. It is not the same glass 

 we have at present. It was on board the ship 18 months after the 

 tyfoon, and we always found it true." 



There seems then little doubt that the anomaly did really occur ; 

 the question then is, " To what can it be attributed ?" 



If, as I have shewn, we suppose the two storms approaching the same 

 point, the Vansittart' s from the N. E., and the Ariel's from the E.S.E., 

 with a heavy N. E. monsoon behind the former, blowing through the 

 whole extent of the trade wind across the Northern Pacific, and un- 

 checked, except partially by the N.W, point of Luconia, we shall have 

 three causes, all tending to augment the atmospheric column not far to 

 the Westward of where the Ariel was on the 16th. I can see no other 

 more simple or more probable explanation. It is however an anomaly 

 to be carefully borne in mind by the seaman, and by all who in- 

 vestigate the Law of Storms, and the more so, that even the Sym- 

 piesometer also gave no indication of the approaching mischief. ! 



* If we were to call it nautical time, " sunset of the 17th" would be sunset of the 

 16th civil time, but there is still a discrepancy wholly irreconcilable, for the Ariel 

 had then had her tyfoon blowing for at least 6' or 9 hours from the N. N. E. The 

 high land of Luzon cannot have occasioned all this anomaly. 



