32 On the prevailing Storms of the Atlantic Coast. 
ion with the great Archipelago of islands which skirt the northern 
limit of the Caribean sea. Of these islands, the three largest form 
an almost perfect and continuous barrier, opposed, obliquely, to the 
progress of these regular winds. Now as the mass of moving atmos- 
phere presses down upon the islands in its south western progress, 
and sweeps along their northern coasts, the obstruction which. they 
afford produces a constant tendency to circular evolution in the mass 
which constitutes the impending or passing current, and which, there 
is reason to believe, takes full effect upon large portions of the trade — 
wind at successive periods, and especially after the parallel or por- 
tion of the trades sweeping north of the islands, becomes narrower 
by the approach of the autumnal equinox. These masses of atmos- — 
phere, thus set into active revolution, continue to sweep along the — 
islands with increased rapidity of gyration till they impinge upon the 
American coast, or encounter oo more regular returning efflux of 
the trades, or land wind of the North American continent. Grad- 
ually assuming a different direction as they recoil from these obstrue- 
tions and receive new impulsive forces, the stormy masses continue to _ 
sweep over, or along the American coast, in a direction conforming, 
generally, to that coast, or to the direction of the Florida stream, 
and in conformity also with the prevailing atmospheric current, of 
which they become an integral part, till they finally become lost, or 
dissipated, at an unknown distance in the northern Atlantic, or per- _ 
haps even reach the coasts of Europe or its northern islands; the 
_ particular course of each storm being no doubt modified by the vari- 
es 
ous oblique winds and other incidents which may attend its progress. _ 
That the foregoing is a just account of the formation of the hur- 
ricanes and severe storms of the West Indies and the lower latitudes 
of the North American coast, is strongly confirmed by the fact, that 
beyond the 12th parallel of latitude, which is a little southward of 
Barbadoes, hurricanes are never known to occur. The more com- 
mon origin or source of the autumnal hurricanes is believed to be 
about the north eastern angle of this great chain of islands; and if — 
we rightly appreciate the operation of these causes, they uniformly 
tend to produce the rotative movement in the direction which has 
been recognized, that is, from right to left, or, in seamen’s dialect, 
against the sun. This course of rotation is understood to be con- 
trary to that which is exhibited in the trades which pass southward 
of the great islands, and which, on reaching the gulf of Mexico im- — 
cline from left to right, with the sun, thus coinciding, or blending, with 
f 
