422 OBSERVATIONS ON THE WINDS. 



There is a large amount of variation, however, in the size, shape, and 

 velocity of these Storms. They are smallest and most violent in the 

 Tropics, where the cloud-ring averages about 500 miles in diameter, and 

 the region of stormy winds 300 miles, or even less. 



Some examples of vessels passing through the vortex are given at the 

 end of this Section. 



(160.) Though the circular theory is now so generally adopted, it is as 

 well here to notice that of Captain George Jinman, who thus expounds 

 his views : — Every Hurricane or Gale has two distinct sides, formed by 

 two currents of air flowing in opposite directions, and crossing each other 

 at two points. The two sides are not always equally developed at the 

 earth's surface — that is, the one often blows harder than the other ; it is 

 but seldom, in fact, that the winds in the two sides are equal in force. 

 The greatest force will be found at either confluence, but rarely of equal 

 force at both. It may blow with hurricane violence at both confluences, 

 and only a moderate gale at the sides.* 



The centre of a Storm is not the most dangerous part. There are times 

 in which it would be possible for a steam-ship to pass from one side of the 

 gale to another, across the centre, and yet not experience more than a 

 moderate gale, whilst vessels on either side of her, under the confluences, 

 may be exposed to violent Hurricanes. A vessel may become embayed, as 

 it were, in a Storm, in such a position that it may be almost impossible 

 for her to escape altogether uninjured. There are many positions, indeed, 

 in which a ship, especially a dull sailing one, may be overtaken, and be 

 unable to escape. 



One confluence is generally more distinctly marked than the other, espe- 

 cially in extra-tropical latitudes; so much so, indeed, that, for a long time, I 

 imagined that there was but one ; which at that time I named the centre- 

 line, or core of the gale. The one on the West side of the centre, in either 

 Hemisphere, is always more marked than the one on the East side. When 

 I say more marked, I mean that the meeting of the two winds may be seen 

 more distinctly ; as, for instance, in the North Atlantic, when the wind 

 flies from S.W. to N.W. This takes place at the confluence on the West 

 side of the centre. On the East side, where the winds forming a confluence 

 are from the S.E. and S.W., their meeting is not so distinctly marked. 

 The wind seldom yZies from S.E. to S.W. ; it more usually veers, but rather 

 more quickly than at any other part of the Storm. The reason is simply 

 this : the S.E. and S.W. winds, flowing out from the Equator, are more 

 highly charged with vapour, and are warmer than a Westerly or Northerly 

 wind, and consequently have a greater tendency to ascend and to mix with 

 each other. A N.W. wind, on the contrary, is a dense, cold wind — a 

 descending wind ; and on coming in contact with a S.W. wind, it con- 

 denses the vapour which the latter has taken up, thus producing torrents 

 of rain at their junction. Here we have one material proof that the winds 

 do not blow in circles ; for, on passing from one wind into another, as from 



* I am satisfied that many of tlaose Storms which have been described by some 

 writers as double Hunicauos or Cyclones, were nothing more than the two confluences 

 of the same Storm. 



