30 On the Prevailing Storms of the Atlantic Coast. 



approach the seaboard the wind will have blown in a more easterly 

 direction, and veering further as we extend our enquiries in that di- 

 rection. If we farther prosecute the enquiry among the records of 

 our nautical friends we shall find a further veering of the wind to east, 

 and ultimately to south-east and south; till towards the opposite or 

 south-eastern margin of the storm its effects will have been felt from 

 south to south-west, and generally to west or north-west, till the cir- 

 cle is completed. 



If the position of a ship on our coast, be within the north-western 

 half or semi-diameter of the storm, it will usually commence from 

 a point to the northward of south-east, veering, ultimately, by way of 

 north, to the westward. But if the position of the ship be within the 

 opposite or south-eastern semi-diameter, the storm will commence 

 between south-east and south, veering afterwards to south-west, west, 

 and even north-west. Rain, or the deposition of vapor in any form, 

 seems chiefly confined to the north-eastern or advancing semi-diame- 

 ter of the revolving mass, though its external or marginal portions are 

 often free of clouds; while most of the south-western semi-annular 

 section or division, displays the appearance of clear weather. Near 

 the frontier margin of the revolving mass, upon the land side, we may 

 sometimes notice the clouds which form the upper stratum connected 

 with the storm, disposed into corticular ranges or layers, of greater 

 or less density, and with various degrees of frequency and harmony 

 in the arrangement. North-eastern storms often blow but moderate- 

 ly, which is to be ascribed to a sluggish rotation, and comprising, usu- 

 ally, a more extensive surface than south-eastern ; they bring to us, 

 in their extensive revolution, the humid and chilly atmosphere of the 

 north-eastern coast. 



As the storms of the North American coast, may sometimes be 

 traced, as we have seen, from a great distance in the general direc- 

 tion of that coast, it may not be unavailing to seek for the primary 

 causes which bring them into operation. 



Owing to the general prevalence of the trade winds in the tropical 

 regions, and which, in the northern Atlantic, extend to about the thir- 

 tieth degree of latitude, the incumbent mass of atnjosphere is in con- 

 stant progress towards the American continent, and into the gulf of 

 Mexico. Continents, and especially elevated and mountainous ran- 

 ges, are well known barriers to the trade winds, which being thus 

 obstructed by the isthmus of the two Americas, restore the equili- 

 brium of the northern hemisphere by a general and regular efflux of 



