Daily globe. [volume] (St. Paul, Minn.) 1878-1884, 1881-03-27
Cyclones.

If we consider the regions in which
cyclones appear, the paths they follow,
and the direction in which they whirl,
we shall be able to form an opinion as
to their origin. In the open Pacific
ocean Gas its name, indeed, implies)
storms are uncommon they are infre-
quent also in the South Atlantic and
South Indian oceans. Around Cape
Horn and the Cape of Good Hope heavy
storms prevail, but they are not cyclonic,
nor are they equal in fury and frequen-
cy, Maury tells us, to the true tornado.
Along the equator, and for several de-
grees on either side OF it, cyclones are
also unknown. If we turn to O. map in
which ocean currents are laid down, we
shall see that in every ''cyclone region
there is a strongly-marked current, and
that each current follows closely the
track which we have denominated the
storm q. In the North Atlantic we
have the great Gulf Stream, which
sweeps from equatorial regions into the
Gulf Of Mexico, and thence across the
Atlantic to the shores of Western Europe.
In the South Indian ocean there is the
'ssouth equatorial current which sweeps
past Mauritius and Bourbon. and thence
returns toward the east. In the Chinese
sea there is the north equatorial current,
which sweeps round the East Indian
archipelago, and then merges into the
Japanese current. There is also the
current in the Bay Of Bengal, flowing
through the region in which, as we have
seen, cyclones are commonly met with.
There are other sea. currents beside these
which yet breed no cyclones. But we
may notice two peculiarities in the cur
rents we have named. They all flow
from equatorial to temperate regions,
and secondly, they are all Horseshoe
currents
Now, if we inquire why an ocean cur
rent travelling from the equator should
be "storm breeder" we shall find a
ready answer. Such a current, carrying
the warmth Of Intercepted regions to
the temperate zones, produces in the
first place, by the mere difference OF
temperature, important atmospheric dis
turbances.
But the warmth of the stream itself is
not the only cause Of atmospheric dis
turbance. Over the warm water vapor
is continually rising and, as it Uses, is
continually condensed Qile the steam
from q locomotive) by the colder ali
round. can observer on the moon, u
says Capt. Maury, "would, on winters
day, be able to trace out by the mist In
the air the path Of the Gulf Stream
through the sea-" But what must hap
pen when vapor is condensed? We
know that to turn water into vapor is a
process requiring -that is, using up-a
large amount Of heat; and, conversely,
the return of vapor to the state Of water
sets free an equivalent quantity of heat.
The amount of heat thus set free from
the Gulf Stream is thousands Of times
greater than that which would be gen.
Grated by the whole coal supply annually
raised in Great Britain. Here, then, we
have an efficient cause for the widest
hurricanes. For along the whole of the
Gulf Stream, from Bemini to the Grand
Banks, there is a channel of heated,
that is, rarefed air. Into this channel
the denser atmosphere on both sides is
continually pouring, with greater or less
strength. When a storm begins in the
Alta tic, it always makes for this chan,
mel, "and, reaching it, turns and follows
it in it's course, sometimes entirely
across the Atlantic. ="
By like reasoning we can account
for the cyclonic sto1ms prevailing In the
North Pacific ocean. Nor do the lorna
does which rage in parts Of the United
States present any serious difficulty.
The region along which these storms
travel is the valley Of the great Missis-
sippi. This river at certain seasons is
considerably warmer than the surround
ing lands. From its surface, also, aque-
Gus vapor is continually being raised.
When the surrounding air is colder, this
vapor is presently condensed, generating
in the change vast amount OF heat.
We have thus channel of rarefed all
over the Mississippi valley, and this
channel becomes storm track, like the
corresponding channels over the warm
ocean currents.-Prot. e. Il. Proctor.