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paper gives a full account of the hurricane of September, 1821, which was 

 traced from the West India islands northward along the whole line of our 

 coast. It contained also a notice of the storm of August 17, 1830, and two 

 or three other storms of the same year. From a comparison of all the ob- 

 servations, Mr. Redfield derived the conclusion that those storms were 

 great whirlwinds. In 1833 he published the following general proposi- 

 tions, as embodying the results of his investigations: 



1 . The severe storms of the Atlantic coast often originate in the tropical 

 latitudes, where they are distinguished by the name o( Iturricanes. 



2. These storms cover, at the same moment of time, a surface whose 

 diameter varies from one to five hundred miles, and in some cases they 

 have been much more extensive. Ttiey act with diminished violence 

 towards tiie exterior, and with increased energy towards the interior. 



3. While south of the parallel of 30° these storms pursue their course 

 towards the west, on a track which inclines gradually to the northward. 

 In the vicinity of latitude 30° their course changes somewhat abruptly to 

 the northward and eastward, and the track continues to incline gradually 

 to the east, towards which point, after leaving the lower latitudes, they ad- 

 vance with an accelerated velocity. The rate of progress may be estimated 

 at from 12 to 30 miles an hour. 



4. The duration of the storm at any place within its track depends upon 

 its extent, and the rate of velocity with which it moves. 



5. The direction of tlie wind over the greater portion of tlie track is not 

 the direction of the progress of the storm. 



6. In the lower latitudes, while drifting to the westward, the direction of 

 the wind at the commencement of these storms is from a northern quarter, 

 usually from northeast to northwest, and during the latter part of the gale, 

 it blows from a southern quarter of the horizon. 



7. North of the parallel of 30°, and while pursuing their course to the 

 nortihward and eastward, these storms commence with the wind from an 

 eastern or southern quarter, and terminate with the wind from a western 



quarter. 



8. On the outer portion of the track, they exhibit at their commence- 

 ment a southerly wind, which, as the storm comes over_, veers gradually to 

 the westward, in which quarter it tenuinates. 



9. Along the central portion of the track, the first force of the wind is 

 from the southeast; but after blowing for a certain period, it changes sud- 

 denly to an opposite point, fi-om which quarter it blows with equal vio- 

 lence till the storm has passed over: it is under this portion of the storm 

 that we notice the greatest fall of the barometer, and the mercury usually 

 begins to rise a short time previous to the change of wind. 



10. On the inner portion of the track the wind commences from a more 

 eastern or northeastern point of the horizon, and after-wards veers by north 

 to a nordiwest or westerly quarter, where it finally terminates. 



11. Hence Mr. Redfield infers that the portion of the atmosphere which 

 composes the body of the storm blows in a horizontal circuit around a verti- 

 cal axis of rotation, which is .carried onward with the storm, and that the 

 direction of the circuit is from right to left. 



12.. The barometer always smks while under the first portion of the 

 storm, and rises again under the last portion of the gale. 



In 1835 Mr. Re'dfield published an analysis of several additional storms 

 which visited the American coast, and accompanied his paper with a chart, 



