22 On the Cyclones of the Noi'th Pacific Ocean. 



From the known law wliicli governs tlie action of revolving 

 storms it follows that the observations alreaclj stated are suffi- 

 cient to show that this gale was an actnal cyclone, moving west- 

 "wardly, in the direction which is common in the trade-wind 

 latitudes north of the equator ; that it was of great superficial 

 extent, and very slow in its progression, and that the relative po- 

 sition of these two ships in the cyclone was very far to the right 

 of the path pursued by its axis of rotation. All this was shown 

 by the direction, persistence, and gradual veerings of the storm- 

 wind, between East and South, and its characteristic effects on 

 the barometer, as w^ell as by the relations of these phenomena 



to the courses and the successive geographical positions of the 

 shi ps. 



There have been instances where vessels in like relative posi- 

 tions in a cyclone have run on in the same course with the storm, 

 for several days, without any appreciable change in the direction 

 and force of the wind; and from which the navigator has infer- 

 red, erroneously, that such gale could not have been of a rotary 

 character ; while the contrary has been clearly shown by the 

 reports from other vessels exposed to the same gales. A better 



knowledge of the cyclones, will enable the mariner to avoid this 

 error. 



We also have further knowledge of the great extent, the slow 

 progression, and the cyclonic character of this storm, founded 

 on observations made in other localities, in adjacent portions of 

 the Pacific Ocean. The U- S. ship Saratoga sailed from Jcddo 

 Bay with the steamships, bound for Shanghai, on a track more 

 westerly than was pursued by Commodore Perry ; it encountered 

 the same strong winds and heavy sea, from nearly the same quar- 

 ter, and was hove to on the 21st, in lat. 29° 01', Ion. 129^ 37', 

 as also on the 23d and 24th, near lat. 30°, Ion. 124° E. ; and was 

 off Saddle Island, near the mouth of the Yang-tsz' River, from the 

 27th to 30th^ the wind having then veered to S, E,, with squalls 

 and continued bad weather. The Saratoga's barometer reached 

 its lowest, 29-60, at noon of the 24th, in lat. 29° 28^ Ion. 128° 

 17', with the -wind at E.N.E., and afterward veering to S.S.E., 

 as with the steamships of the squadron bound to Loo Choo. 

 "We have no observations from points nearer to the right border 

 of the cyclone. 



We have next the report from the master of the U. S. ship 

 Supply, then lying^ in the harbor of Napha, Loo Choo, in lat. 

 26^ 12' N., Ion, 127° 43' E. This shows that the anterior baro- 

 metric wave of the cyclone had reached Napha at noon of the 

 12th, barometer S0'02 inches. It then slowly subsided, with 

 winds from easterly points, until it reached 29-84^ on the night 

 of the 17th. The wind freshened, and was strong on the 18th, 

 with a continued fall of the barometer. On the 19th and 20th 



