The Pensacola journal. (Pensacola, Fla.) 1898-1985, 1918-08-26

most OF them come from the Dol
drums"
The Reason for Hurricanes
While on the question of hurricanes,
1t seemed we'll to inquire what makes
them originate.
That's a fair question, though
big one: one that has not yet been sat-
isfactorily answered by meteorologists
Prof. William Terrell, who was prob
ably the greatest of mathematical
meteorologists, has this explanation TO
make:
''All storms are produced by an as
cending current OF warmer atmosphere
saturated with moisture, and this cur
rent is kept in motion by the continual
rarefaction of the atmosphere above
by means of the caloric (heaD given
out of the water which is condensed
as it ascends to the colder regions
above.
Therefore, as long as the ascending
current can be supplied with air sat-
urated with vapor this continued rare
faction must take place. If, then, all
the lower stratum of atmosphere over
large district were saturated with
vapor, without some disturbing cause.
it might remain undisturbed; but, if
from any cause. an ascending current
is produced, either by local rarfaction
of air by means of heat, or by the
meeting of two adverse currents, which
produce gyratory motion and conse-
quent rarfaction in the middle on &C
count of the pressure being taken
away by centrifugal force, as soon as
the air below, saturated with vapor,
ascends to the colder regions above.
the vapor is condensed and the caloric
given out continues TO rarity it so long
as the ascending current is supplied
with moist air. The surrounding cold
Comparatively speaking) air presses
in below from al Sides and thus a
storm of more or less violence is pro-
duced, moving with the general di-
rection of the motion of the atmos-
phere where it occurs. The violence,
then, of a storm, and also its duration,
depends upon the quantity of vapor
supplied by the currents flowing in
below. Hence it is that the tropical
hurricanes which originate in the At
lantic east of the Caribbean Sea (the
Doldrums) do not abate their violence
until they reach high northern lati-
tude, where the atmosphere is cold
and dry.
Some Come Back
you ask if storms really come back
as some people seem to think because
the storm we had in September, Ie17,
first blew from the east and southeast;
then there was a lull, and suddenly it
came back and blew from the north
west"
Some storms do come back. think
it was in 1910 that severe storm
came up from the south and struck
Havana, moved off into the Gulf and
made a complete circle. coming back
to Havana two days later with ever
greater intensity, then recurved and
moved northeastward over the Florida
Peninsula. But that is rare The
storm you speak of coming back in
1917 was moving along a straight line
Or nearly so. The wind only shifted,
which it does in all storms
The 1917 storm passed right over
Pensacola, causing the shift to be more
this shifting of the wind in storm
as briefly as possible
"As / said before, the air in the cen
ter of storm rises along curved edgeT
(due to the rotation of the earth on its
axis. This flow air is generally called
winds. 1t is a popular fallacy that the
winds cause a storm and may blow it
away in another direction. This is not
So; they are the result, not cause. The
winds, therefore, blow from all direc-
tons toward the center of a storm.
easterly winds, the storm center must
be to the north, etc. In the spot,
sometimes with a clear sky, which is
called the 'eye of the storm" Now if
a Storm comes up from the Gulf, say
southwest of Pensacola, you will have
at first northeast and east winds, and
If the center passes right over this
place, you will have a short calm or
lull, and then as the storm goes on we
will be on the other side of it, and the
winds will come from the west and
northwest. This shift of winds only
occurs when the center passes over
or nearly so. the place of observation"
Climate Not Changing
"You said that during the S5-year
period from 1876 to 1911 there We're
143 hurricanes charted, and that less
than half dozen of these touched
Pensacola. Now, in 1915, and 1917 we
had three very severe storms, and
some people are beginning to think
that conditions have changed and that
more storms are coming this way than
before Do you think that our climate
is changing" asked the interviewer.
mo, | do not was the reply. I'VE
had last year the coolest December on
record, and this month we came pretty
near breaking the record for high tenn
peratures. But that does not indicate
anything. We have everywhere per.cS;s
of cold, periods of warm. periods of
dry and wet, and also as it seems Pc
RODS of storms, but all meteorologisls
agree generally that climate has not
changer anywhere within historic
times. And when say climate, | mean
average conditions to differentiate