Mr Lawson on the Trade-Winds of Barbadoes. 371 



As the current flowed through the breach thus formed in tho 

 lowest stratum of the atmosphere, its velocity could never 

 be sufficiently reduced to admit of its accumulating, so as to 

 restore the equilibrium of pressure, but it would tend to 

 elongate the breach, in a south-westerly direction, the first 

 portions propelling the still air in that direction, and those 

 which follow gliding above them as they became retarded by 

 the resistance they met with. 



55. The difference of pressure within the storm, and be- 

 yond it to the northward, now becoming very considerable, 

 would cause the lower portions of the comparatively still air 

 around its northern margin to flow towards its centre, still 

 retaining, however, more or less of their easterly tendency. 

 As soon as these became mixed up with the original current, 

 their velocity would be farther increased ; they would be 

 swept away, in fact, by the rapidity of its motion. 



56. The upper portion of the trade-wind being thus di- 

 rected downwards, with great velocity, retains its easterly 

 tendency unaltered, but the southerly motion is much greater 

 than usual (2), and the wind, instead of being NE., or ENE., 

 will at first be experienced from NNE. In consequence of 

 this alteration in direction, that part of the trade to the west- 

 ward of the storm being no longer backed up as before, will, 

 while flowing southward, have its easterly tendency checked, 

 and will gradually flow towards the line of least pressure 

 (as between NW. in fig. 2), being felt as NNE., or N. cur- 

 rents ; and thus joining with the one already flowing in the 

 same direction, will gradually acquire the same velocity. 

 The upper part of the trade-wind would obviously be first 

 affected, and subsequently, that below, and the storm would 

 move slowly to the westward, the first indication of its ap- 

 proach being a gradual fall of the barometer. 



57. While these circumstances are occurring on the north- 

 ern and western sides of the storm, others of an equally 

 important character must be taking place on the eastern 

 side of its line of least atmospheric pressure. The upper 

 strata of the trade-wind, which were originally moving from 

 the north- east wax'd, with the same velocity, and in the same 

 direction as that portion which has been deflected down- 



