The New Orleans daily Democrat., 1878-06-07

| liiR iaSb enough, mas us VeiOtltE gLodCiy az
celerated by the newly created demand, anC
| the result is tornado. The tornado has
many pecuiarities. After being formed il
| rusheS along at the same elevation, and hay
ing gained the top of d hill opposing its patti
| it Jumps impetuOusly across the valley, ever
a wide shallow one, to the top of the next hill
and the valley escapes its fury. II the next
hill be higher than the last it plOws into it,
carrying dust and soil up into the air and
scattering them from above in all directions
| This Is the reason why we see it telegraphPd
that the tornado sometimes rose in the all
and then returned to the earth with renewed
and increased fury. If, after rushing on lis
destructive path over the plain it meets
n hill-then there is no time for par
ley. Either Che hill or the tornado must give
way at once. Consequently the tornado is
cleft in twain, if OF any size. The tornado
uses up an immense quantity of air which is
drawn in below, heated by friction and by
sudden rarefaCtiOn, aSCendS rapidly and flows
over above. This heating explains why it
scOrches the grass. experiences less resist
anCe from hot air than from cool, COnSe-
Quently 1t moves towards the hottest locality.
After a tornado has been divided the parts
must be driven far from one another, or they
will reunite (by using up most of the air be-
tween the seCtiOns) into a larger tornado than
before. For, when the air is rarified between
them, on account of helping to rapidly supply
both, then they move most easily through this
raritied air. which Is less capable Of resisting
JIttIu. Accordingly bntN near bIlh HllObLfI
and this uses up the air between them still
more rapidly, partial vacuum Is created
there, and bang! becomes the pivotal point
of both, Thus reunited at point where they
have combined TO use up so much air. the in
rush from around must be intensified in
violence, and the consequence is that the tor
nadO is amplified to a size and violence
greater than before the separation.
1t must be an awful sight to see one of these
destructive phenomena jump, black and
linz
another, through the darkened air, under q
lowering sky. and distributing it's cargo Of
leaves, dust and spnters, animals and old
women, in all directions Outwards from the
threatening summit of its roaring vortex,
more especially as 1t is always accompanied
by strange roaring sound, perfectly ap-
palling when one feels that he is not at safe
distance.
The poet was. probably, at tolerably safe
distance when he sang half adnltrtngly about
How beat and tempest mngIe in n maze
Or beCh in thunder or in lightning blaze;
How soaring females scOOt around on high
When bold tornadoes buster in the sky"
And now, finally, if anybody wants to illus
trate for himself by a very simple expert
ment, how the direction of the wind changes
during the passage of storm over a city let
him take a sheet Of semi-transparent paper
and draw upon it a circle, From several
points, on the circumference of this figure,
let him draw as many lines as desired CirCing
around the interior of the circle and gradual
ly approaching the centre of it.. Then draw
the paper with its figure slowly over fixed
black point or spot on his desk or table, and
as the lines CirCling inwardS represent the
direction of the wind he will see how it veers
during the progress Of a storm. He will see
by this experiment why the wind goes veer-
ing around by the south when the storm
centre passes to the north of New Orleans.
for instance; and why, mutGtis mWtdndis, it
goes UiCe versa.
Hem excuse me, that is too "scientific"
way OF saying it. | mean that he will also
see why the wind 'baCks" around by the north
when the storm centre passes south of New
Orleans.
If, then, he will take two black spots on his
desk and draw the figure over them so that
the "Centre" will pass between them, he will
see why the wind in the same
storm "veered" in the vicinity of one of the
ships mentioned near the beginning Of this
article, and ''baCked'' in the vicinity of the
that is changed all round with both,
but went in opposite directions. The figure
here recommended should be at least four
inches in diameter, and the lines drawn inward
need make but one circuit round the Storm"
The summer storms of the United States
are not yet sufficiently studied, but they are
treated as similar to the winter storms.
these winter storms are often called cyclones
when they are violent enough. In other re-
5peCts they are precisely similar. Some au-
5hOritieS COnfOund tOrnadOGS with hurricanes.
Typhoon is often applied to what we in
America would call a cyclone andalso to what,
we call tornado.
There now remains but one thing to beex-H
llained, and tits this: For fear Of cncumberingi
he above with too many details credited Red i
ield with discovering the true laws of storms,
ls received at present The truth is, he came
very near it, but did not entirely succeed
His theory was that the wind blew in circles
'Ound and around the storm. The OthGrI
American philosopher, Espy, held that the
wind blew in straight lines towards the
centre. Both presented innumerable facts
bearing out their respective hypothesis.
1t was Prof. LOOmis who, having minutely
the facts adduced by both these
great men, discovered the true theory, which
s the mean of the other two, and is now uni
yersally accepted-viz: that the wind blows
,ircularly and spiralIy inwards towards the
storm centre. His book, "Loomis Treatise on
was published in New York in
1870. 1t is clearly and ably written, and very
interesting, and cheap. G. JR.
q As