San Antonio daily light. [volume] (San Antonio, Tex.) 1886-1907, 1888-01-21

respective ends pointing In the direction
Indicated, and then move II directly
eastward giving regular turn while so
doing, until IL leaves the eastern coast
pointing sOntheAstward, IL Will indicate
tolerably clearly the front line Of these
storm waves In their passage across the
continent.
Now the question may be asked, why
do these storms come so generally from
the northwest? Why not come as well
from any other direotioDf 70 answer
these questions we must 20 back TO the
early part of the article and resume the
discussion OF general principles.
Observations extending across the
hemisphere both on this continent and
the eastern, across the ocean and around
the polar circle show these facts, name
ly: That there Is a constant circulation
going on between the equatorial and
polar regions Induced by the higher
temperature Of the atmosphere In the
tropical belt and the daily rotation OF
the earth: that the surface curl ents first
take a northward course until reaching
the latitude OF 30 degrees OF the parallel
OF this CITY, when they begin to change
to the nOrtheastward and continuing
around the globe and encircling the
north pole they may be said to reappear
on our northwest border angered by
their bitter experience during their long
Journey 10 the Arctic regions, and
incoming more dense, therefore more
powerful for overcoming obstacles, they
are enabled to sweep southwark over
the country until they meet the oppos-
ing force on the border OF the tropics
which first started them on their north
ward course.
There are some important and very
interesting facts connected with these
wave movements. But We will fret ex'
plain by saying that the atmosphere
moves in waves and eddies like the sea.
Air 10 motion never moves In straight
lines. This anyone may see demon
strated by observing the movements or
light objects like dust or feathers, when
they rise and fall and take Zigzag
courses with the currents; again the
constantly shifting movements OF wealth
er yanes; which are scarcely
stationary even 10 light winds for a
second. On the same principle the
great waves do not move In straight
lines. The convexity Of the globe and
the elevations and depressiens on Its
surface influence the atmospheric move
ments greatly to say nothing OF the ef-
boat ard
iects Oh unequany uistlipueu nos' NM
the dlnerence Ill 'empera'ure vi ia"u
anu sea.
Again the cold waves. indicate high
bsrometrio pressure or greater weight.
In front OF them there is always q
trough of low pressure In which the air
is warmer and which contains more
moisture. This warm trough should al
ways be accepted as due notice that
cold wave will soon be at hand. HAD
this most Interesting TACT Deen uuly>
needed by the people 10 the northwest
there need not have been q single human
life sacrificed. There was plenty OF
time to get ready for the blizzard hours
before IL reached them. Ii should nave
been published that the unreasonable
mild day brooded danger, the more SO
that II was so different from the usual
cool fair weather OF that region. we
had foretaste OF 1t here. Inc warm,
almost sultry weather OF last friday ana
Saturday Indicated great atmospheric
perturpations not very remote ana the
direction ofthe winds and clouds pointed
to the northward as the source OF