On the prevailing Storms of the Atlantic Coast. 49 
which corresponds sufficiently with the usual diameter of the lesser . 
storms, and also with the probable breadth, in latitude, of that por- 
tion of the trade which, in the stormy season, is subject to this influ- 
ence. Now the immediate effect of the rotative motion in this mass, 
will be to induce, in some degree, a counter gyration in the diurnal 
mass which next succeeds it, and which has not yet become subject 
to the original rotative influence. ‘The previous tendency, thus im- 
parted, will enable the second diurnal mass to pursue its course along 
the islands on the following day, in a comparatively quiescent state, 
which is induced by these contrary influences. But not so with the 
third diurnal succession of atmosphere, which, previous to its arrival, 
has perhaps already felt the influence of the counter movement of 
the second mass, somewhat in*the manner in which toothed wheels, 
by their external contact, communicate motion to each other ; and 
this diurnal mass, thus predisposed, may receive the gyrating impulse 
with more facility than either of the two which have preceded it. 
By parity of reasoning, the fourth day would witness the passage of 
4 comparatively undisturbed atmospheric current, while on the fift 
day an increased disposition to gyration would again occur, and so 
alternately, on the succeeding days. These successive diurnal in- 
fluences, though subject to all the collateral influences which may 
chance to attend them, may notwithstanding, be supposed to produce 
some discernable effects, and, in the usually regular progress of these 
winds towards the continent, and afterwards in the general direction 
of the coast, these diurnal effects might be supposed 
at a great distance from their original source. 
It may happen at some seasons, that the causes which produce 
the revolving impulsion, operate upon a still larger portion of the at~ 
mosphere, equal, we will suppose, to the space occupied in the ad~ 
vance of two days, and some also of three days, as seems to be the 
case with some extensive storms or hurricanes. Now in most of 
these cases, whether in periods of one, two, or three days’ dura- 
tion, their termination will coincide at the end of the sixth day.* On 
the seventh day, therefore, a renewal of the original revolving influ~ 
ence, may again be expected to occur. Whatever may be thought 
ieee can ee a CT 
* At St. Augustine, in Florida, where the storms from the vicinity of the islands 
frequently appear, it is said that a storm which continues more than one day, will 
last three days; and ag poculnty, says continues to be observable till the 
storm has advanced a h greater ce along the coast, but with less exactitude. 
in proportion to the Sait from pi sha of its origin. 
Vor. XX.—No. 1. “§ 
Mo. Bot. Garden, 
i901. 
