338 EXPEDITION TO JAPAN. 



was of great superficial extent ; and that the position of these ships was far to the right of the 

 path pursued by the axis of the gale. It is equally apparent that it belonged to a class of gales 

 which are distinguished by the sluggish rate of their geographical progression. All this was 

 manifested by the persistence of the easterly winds ; by the slow and graduated effect of their 

 cyclonic action, as seen in the fall and subsequent rise of the barometer ; and by the gradual 

 veering of the winds towards the south, as the cyclone passed off. It has sometimes happened 

 that a ship placed in a similar position in a cyclone, has run in nearly a direct course parallel to 

 its path, for several days, without any considerable change in the direction of the storm wind. 

 Hence it has been inferred, erroneously, that the gale was not a cyclone. A better knowledge 

 of the cyclones will enable the mariner to avoid this error. 



But we have further knowledge of the great extent and slow progression of this storm, 

 obtained from direct observations in the adjacent parts of the Pacific ocean. The Saratoga, 

 which left Yedo bay with the steamships, bound for Shanghai, on a track more northerly than 

 was pursued by the steamships, encountered in like manner the heavy sea and strong winds from 

 the eastward ; and on the 21st was hove to, in latitude 29° 1', longitude 129° 37' ; and likewise 

 on the 23d and 24th, near latitude 30° N., longitude 124° E., and was off Saddle island, near the 

 mouth of the Yang-tsz river, from 27th to 30th, having then southeasterly winds, with squalls 

 and continued bad weather. The barometer reached its lowest point, 29.60, at noon of 24th, 

 in latitude 29° 28', longitude 128° 17', with the wind at E.N.E., and afterwards veering to S.S.E., 

 as with the steamships. We have no observations made nearer to the right border of the 

 cyclone. 



Next in order of the gale's progression, we have the observations found in the master's report 

 of the United States store-ship Supply, then lying at Napha, Lew Chew islands, latitude 26° 12' 

 N., longitude 127° 43' E., a position much nearer to the center-path of the cyclone. His tables 

 show the maximum of the anterior barometric wave to have reached Napha as early as noon of 

 the 12th, when the barometer stood at 30.02 inches ; from which time to the night of the 17th, 

 it slowly subsided to 29.84, with winds from the eastern board. On the 18th the wind had 

 become strong, with an increasing fall in the barometer. On the 19th and 20th the gale blew 

 from the northeast quarter, with increasing violence ; and in its greatest force from the north- 

 ward on the 21st. At 3 A. m. of this day the barometer had subsided to 28.88 ; and to 28.82 

 at noon, with a slight reaction at evening. At 3 p. m. of 22d it had settled to 28.74, its lowest 

 point, from which it had only risen to 28.83 at midnight, with improving weather. On the 

 23d and 24th the wind veered through east to southeast, and the barometer rose more rapidly. 

 It reached 29.80, the July mean of the region, on the 20th, when the wind had veered to south, 

 with no further traces of the departing cyclone. The fall and rise of the barometer at Napha, as 

 also with the other vessels, was not entirely gradual, but with very moderate fluctuations of 

 some hours continuance, as is more or less common under other wide-spread cyclones. The 

 gale, though of much violence at Napha, was not of the greatest intensity of hurricanes. It 

 was observed by the officers "that even when the wind was piping loudest — -when the water 

 was whirled violently by in perfect sheets — the scud moved overhead at a remarkably slow rate, 

 and the upper layer of clouds seemed scarcely to be stirred at all ;" thus showing the very 

 limited elevation of the superior surface of the cyclone. Its axial center, when near these 

 islands, probably bore south from Napha near noon of 22d, at a distance which I now estimate 

 at about eighty miles. 



In further tracing its approach to the western limits of the Pacific, we have the log-book of 



