The Washington herald., 1908-07-17

storms, accompanied by thunder and
/ lightning, are in season, and before this
evenings sun sets Washington may have
a practical display Of what tn clements
can do in the line of phenomena. not
/ withstanding the forecast Of the Weather
/ Bureau and St Swithin that it is not go
ing TO rain for forty days to come
1 The clouds which foretelI a storm. ac-
cording to the initiated AT Uncle Sans
Weather Bureau. are the cirrus clouds,
mares tails" the country folk call them
i-hairlize shreds threaded across the
heavens. later gathering into cirrus
stratus. white and gray cloud sheets.
which are the true rain clouds. The at
mosphere is always heated. with a sultry
humidity. II is warm and moist. thick.
heavy. muggy. It sometimes almost feels
wet. People often then speak Of feel
ing" the rain in the air There is rarely
any wind preceding a storm for any
length OF time; the air is exceptionally
still AS the tempest approaches nearer.
[ however. a soft thick. wet sort OF
''whirr' characteristic as a harbinger Of
the rainstorm at its heels. is felt stirring
abroad This is familiar TO all those who
have made a study Of weather conditions.
and is as easy OF recognition as the aw-
ful oraeles Of the weather prophet mon
strosiJies on feet
II Favored Hours for Rainfall.
The time Of day when rain IS most
likely TO fall is about O'Clock in the
afternoon. OF. again. between , and
4 O'Clock IN the morning. These are the
two turning points in the days tempera-
ture- At O'Clock the maximum heat
I usually has been reached for afternoon.
/ while at night the GOODNESS has thor
/ OUghly set in IN case OF a succession Of
! Jhunderstorms. they usually occur about
! twenty-four hours apart, that being. ap-
. parently. the time necessary for them TO
I accumulate sufficient moisture 10 break
/ SO. II a storm series begins in the after
noon. the remainder Of the series VIII
likely take place in the afternoon. while
If it begins at night the storms are likely
10 continue to be al night
II It is considerably easier 70 foreteH ac-
curately the arrival Of thunderstorm
than 10 explain it after 1t has come
Wiser than any man nov known would
be he who could follow understandingly
the magical metamorphosis Of the chart
ing summer landscape, with its lake Ike
from the time the first misty sultriness
arises as the threatening breezes begin
20 stir; as the sky darkens frOwningly.
the winds break boisterousIy from their
| fet;ers. the cloud streams pour out in
II cataracts, and the fires OF heaven illu-
inmate the tempestuous night with their
I terrible play, and. finally, as the eIe-
ments again calm themselves, the sun
breaks out and rsvivihed nature becomes
|. doubIy lovely.
I The first clew to the mystery Of
storm comes from water- II a glass OF
water is stood on a WINDOW sill on hot
day il gradually evapora1es. The hot.
I dry air sucks il up Similarly. the hot
dry air above q large body OF water sucks
up its water, transforming IL into a fine
i vapOr. which imparts a mistiness 10 the
atmosphere. The distant atmosphere now
gradually screens itself ii a veil Of vapor,
Y which becomes thicker and thicker. This
leads 10 the next phenomenon in a thun-
\ derstoTm-
Il Electricity Always Present.
L Every one presupposes an accumulation
+ OF electricity in a thunderstorm EIec-
tricity is present in the atmosphere all
. the time. but Il is always more powerful
+ when any strong perpendicular currents
OF air are in action. such as cyclones, tor
nadoes, volcanic eruptions. waterspOuts.
or thunderstorns- Electrical manifesta-
tons are always accompanied by the
downpour Of water This means that the
condensation Of vapOr is closely connect
ed with electricity. IN a thounderstOrm
II electricity is generated by the friction Of
! individual particles Of water which have
/ been driven about By the wind
The two kinds OF electricity. positive
I and negative. always try TO unite. The
( ascending portions Of the air, and the
/ clouds generally, are charged with mega
I tive electricity while the surface Of the
/ earth over which they swim are charged
with positive electricity Each seeks TO
unite with the other. The majority Of
[ the particles are not strong enough IN
I electricity 70 span the space Of air lying
! between. and can do so only under high
/ tension. AS the friction Increases, cleo
/ tricity accumulates on the hrims Of the
I clouds and the projections Of the earth's
1 surface. trees. houses. and mountains
1 The Currents Of air become sturdier.
/ They bend the bouEhs Of the trees.
scOurge the waves. lash the ships. The
last feeble sun-rays break through the
massy clouds. casting an unusual, threat
ening, and uncanny light over the scene.
/ The clouds gather, more and more thick
I ". Transforming themselves from the
/ light cumUlus clouds to rain clouds The
struggle Of the negative and positive poles
/ Of electricity becomes more savage
The Electrical PhenOmena.
If a metal ball is charged with cleo
/ tricity, only the surface becomes mag
netic- The interior IS not electrified.
Similarly, the microscopic drops OF water
| forming the clouds are electrical only
/ on their surface. Through the ever great
/ er condensation they come nearer and
nearer. and finally many together form
one large rain drop. This larger rain drop
contains all the electricity Of the many
smaller drops, but as its surface is more
limited than their combined surfaces its
| electricity is Of greater power
The rain drops. toe large and heavy
/ to hover in the air. fall to earth As the
clouds merge rain drops form more and
more rapidly, and the rain fails more
violently and copiOusly. The storm is
now fully developed, and unburdens it.
self with fury. Brilliant flashes Of light.
! produced by powerful electric sparks,
/ illuminate the, darkness and the thunder
growls in the sky. The tension between
1 the surface of the earth and that Of the
/ cloud has become stronger. The tracts
/ Of air. which at first were too vast TO be
/ traversed by electricity, are now the path
/ way Of lightning, not only between earth
I and clouds. but also between cloud and
cloud. negative and positive poles meet
I ing whenever strong enough TO cross the
necessary space
] fs~h-