The Mankato free press. [volume] (Mankato, Blue Earth County, Minn.) 1879-1924, 1885-08-07
THUNDER.STORMS.
Something About Their Actions -
Learned from Balloon Investigations.

Something About Their Actions ~
| Learned from Balloon Investigations.
The form of the cloud-mass as we
see 1t from the ground Is not well
shown, but as described by Wise, the
aeronaut, from his balloon voyage
made thirty or forty years ago, 1t has
somewhat the shape of great hour
| glass, the ark-shadowed clouds enter
Ing as they form at tho base, and pre-
sumably rising through the central
construction to supply the white. sun
lit mass that Is rolling out at the top
18th the appearance OF vast sea of
Jhow, boiling and unheaving from In
formal commissions. Zigzags Of light
| ming dart from one cloud-mass TO an
other, or blaze out in tho gloom be-
tween the clouds and earth, or even
| flash from tho clouds into the open,
empty sky; but the origin of these
violent electrical manifestations is al
most as much mystry as it ever was.
The condition under which electric
sparks, large or small, arc discharged
is fairly we'll determined, but the ulti-
n q questioneA which physicians are
not yet agreed. When lightning
flash is viewed ut night through mar
row radial slit in a rapidly-revolving
disk it is found to consist of several
discharges separated by intervals too
short to be noticed by the unaided eye,
but discoverable in this experiment by
the fact that the slit is commonly seen
in several different attitudes when
illuminated by an apparently single.
instantaneous flash.
The apparatus may be easily con-
strncted and used by any high-school
boy or girl. and the fact that it dis
covers is remarkable one in the phys
les of thunder-storms that need more
explanation than it has yet received.
Photographing lightning-flashes at
night is another interesting expert
ment that may be tried to advantage
in these modern days of amateur pho
Biography and instantaneous plates.
Some very successful views have been
taken, showing a composite flash to
consist OF several separate lines of
light, every one irregular, but all close
ly parallel to one another; fine, thread
like branches arc given off at different
points and disappear as they divide
into fainter and fainter fibers in the
dark sky. Returning to the high cloud
mass, ii any venturesome balloonist
ever ascends through the raging vortc.
to its massive summit he would hf4t
opportunity to prove or disprove
suggestions that have been made
mechanism of the storm.
Surprising him bold enough to be-
his ascent under the center of
storm, it is probable that he would ris,
slowly at first, for it is thought that
the falling rain-drops cause down.
ward carrent of air here which would
retard his upward flight; this current,
chilled by the rain, is most likely the
origin of the cool gust of wind that
precedes and accompanies this heavy
rainfall at the storm center. Mount
ing we'll into the clouds, further ascent
would there be aided by the upward
current, to which the formation of the
cloud and storm is thought to be due.
Only the larger drops of rain can fall
through such an ascending current; the
finer water particles may be carried
higher until they are frozen into minute
hail-stones, most of which melt before
reaching the ground as they fall to one
side of the up-draft; but if il happens
that they grow to considerable size
by accretion, they may fall fast enough
to reach us unmclted. Going higher
still, the vapor that is condensed at
these greater attitudes, where the tenn
perture even in midsummer is below
freezing, forms snow-tlakes, and of
these the boiling summit masses of the
storm are supposed to consist
The height to which these superb
nln Il,
but it is very probable over five miles,
and may be over ten; a little observa-
ton will settle the matter, for to take
practical case, if thunderstorm passes
centrally over Arlington, Medford,
and Maiden, as would be known by
the drcnching rain recorded by obscrv-
ers there, the angular altitude of its
white cloud-tops could be estimated by
observers in other towns to the north
and south at certain hours,-as is pro-
vided for in the plan proposed by the
Meteorological sOciety,-and then it
would be easy enough to calculate the
height. But it must be borne in mind
that the explanation of the storms ac-
ton here given might not be generally
accepted, and it is with the object of
learning more precisely what the facts
of the case are that the observations
above referred to are to be undertaken.
The essential points of the method at
first are the selection of a number OF
simple phenomena, such as time when
the rain begins, the direction of the
wind, and so on, which can be OBJ
served by any intelligent person, even
without meteorological instruments;
the undertaking is thus brought within
the reach of that large class of our
busy population who are interested and
willing enough to give some assistance
in such work, provided it does not re-
quire much time and need no special
technical instruction or outfit.
Scholars in our high schools are
abundantly prepared to do effective
work in such school as this. Second,
when thunderstorm appears in sight
or bursting it is important to know the
conditions of wind, rain, ETC., and the
same moment in number of different
places; and to gain this knowledge OBJ
servations are to be made at certain
even hours while the storm lasts. OF
course observations at other times and
in greater detail than here mentioned
will be of no value, but these simple
ones are the most essential. To ac-
complish the desired result, volunteer
observers are to be appointed in the
New England towns, the earlier, we'll
recommended applicants being given
the preference when number apply
from one place. Boston Journal.
Blasted Hopes.