New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1896-03-03
HOW STORMS ARE FORMED
AN INTERESTING LECTURE Ely FORE
CASTER DUNN.


THE BLIZZARD OF 1sss
Forecaster Elias B Dunn the head OF the local
Weather Rurcau lectured last night in Columbus
Hall In West Sixtieth ST. near Ninth-aVe. HIS
lecture was one of the series he has been giving
in the various schools Of the city under the eu-
tnorization Of the Board OF Education, anu Vi
course he talked. like the maids in the flra'es
of penzance" about the weather. An audience
which filled the large nall from stage 'front.' u
gallery TOP gave the closest attention both to
the words of the lecturer and to the ILLUSTRATIONS
which he apt!y used to explain the scheme by
which the signal Service Bureau arrives at its
conclusions 1t is ia. not generally known
that the study of the weather from the maps
furnished by the Bureau is now part OF the
education of children in the New-York schools
II IL taken I'D in connection with the review oy
the pupils OF physical geography, and II Is ouii
schoolboy indeed. who cannot size up coiu
wave on its way down from the area OIL NIB"
pressure in the Northwest and Know just wig"
10 get out his skates. The young maidens nave
not vet begun to gauge their warnings for spring
hats by this unfailing method, but the time prop
ably Is rapidly approaching when they WILL
In his introduction last night to the Columbus
Hall audience the Sergeant outlined brleny the
design Of the Signal Service Bureau. and after
paying tribute I, the newspapers FOR their I'D
eralitv in widening the influence Of the service,
he turned TO the consideration OF his maps. ihese
were stereopticon reproductions of the indication
maps issued from day to day by the service ana
scattered far and wide over the city. and with
their aid he made delightfully."- clear TO the as
semS,ly exactly how storm is formed.
II has been discovered by the Bureau during
ITS long experience covering now period OF
more than twenty-five years. that the storms
which sweep over this country form most gen
orally in the Northwest and clear out upon the
Pacific Slope. The great winter storms gathei
in the warm waters Of the Pacific Ocean, down
as low as Lower California. and pass northward'
gathering moisture as they go. They cannot
oct across the mountains intact. as there their
force Is dispeiled by the cold air. which con-
denses their moisture and dissipates them. ms
IS the familiar cause for the va-t extents OF arid
land known TO the world the Great American
Desert.
Rut right here he showed a peculiar circum-
stance of the weather The process OF irriga-
,io, &c likely TO have beneficial effects in more
ways than one it has been found that after
storm has started for the eastward in good
shane II Is frequently DETECTED to the south
ward This is due to the constant irr1gaton Oh
millions of acres Of what was once dead SOIL.
The moving storm centre finds moisture IN those
lands now 10 feed on, and 1t passes down east
of the Rockies and after taking on new vtaf-
ity so to speak, turns once more to the eastward
and northward leaps the Mississippi, then passes
on to the Lake region and so to the -. Law
renee Valley and out TO the Atlantic.
BY arrangement with foreign countries. the
Sergeant remarked, news Is exchanged ana the
Signal Service officials here at once cable 10 inc
other side intelligence Of the storms progress.
haiv,x Ennu
ress can pretty accurately be measured, anu
mariners are warned what course to take ~
avoid it, If the storm centre shows tendency
to move to the south. ships are warned 70 ooi,,e
westward on the northerly route; II II passes 10
the north, ships turn TO the sou.nward, ana 81
avoid much trouble. -.
This led the speaker TO discussion OF tne
two motions of a storm. one Is Forward OF pro
gressive and the other is rotary. For instahce'
Suppose that there is an area of low pressure,
as is often the case. in the Lake region. Al
vacuum and dry airs come flying from areas OF
high barometer and try to force their way TO the
about the central point looking for an opening
as it were. The direction of the wind at various
stations over the country proves the rutn OF tnis
theory to the officials. The WINDS pass IN q CT
Gle and the amount of resistance they meet Is
one of the causes of hurricanes. 1t Is not the
progressive motion of the storm centre. but the
rotary motion of the winds about II Wnlcn II
TO be feared.
The Sergeant in dealing with this storm
question referred 10 the prevailing weathei coh-
ditions. He said that the storm. of which the
rain Of Sunday and the snow of Sunday night
were the outcroppngs, began in an innocent
sort of way clear down in Texas. II was a
small Of low pressure and required until
Saturday to reach point near Virginia. There
il took on new force and passed northeast
wardly through New-Jersey Its conditions
precisely similar. up to a certain point, to
the great blizzard OF 1883. which began in rain
and ended everybody knows in the frightfu
period of cold and deep drifts. with the differ
once however. that In the blizzard the storm
centre happened to strike just at New-York
City, and there remained stationary for time
The storm OF Sunday moved onward. New con.
ditions were created and the city enjoyed the
clearing weather which appeared about II
o'clock yesterday morning although the winds
were high for some hours BY picture and
.learly worded explanation the speaker made