The midland journal. (Rising Sun, Md.) 1885-1947, 1914-02-06

AHs ENFeH NIS oSyOua 8uStF nCACU
and Are Consequently Unknown Fac
tors-Methods Of the f.ncients.
The art of predicting the weather is
one In which it seems at first sight the
modern scientist ought easily to sur
pass his ancestors. Yet it may be
doubted whether he is really more
successful in 1t than they were. The
meteorological department boosted
some time back that their forecasts Of
weather as published in the daily press
were justified by the result In SO per
cent Of the cases recorded. As the per-
centage Of correct guesses in suffl-
GENTLY extended list. however, would
exactly equal the incorrect, this does
not show very great superiority for
scientific methods over pure conjec-
fure.
Yet the meteorological department
enjoys the advantage. as our ances-
tors, OF course, did not. Of elaborate
and accurate recording instruments,
Ike Secchi's meteorograph. together
with telegraphic reports from weather
stations dispersed nearly al over the
surface of the globe. Its relative nom
success shows perhaps that there is
still factor in the problem which it Is
at present impossible to estimate
| This is the more extraordinary be-
cause the modern method of forecast
Ing the weather differs entirely from
that practiced by the ancients. With
them it was simply question Of time
q season, or, what Is the same thing,
Of the appearance or disappearance OF
certain stars.
When Hesiod's husbandman saw the
Pleiades he knew it was time for him
to begin his harvest, and when they
set forty days later. his blowing. This
might still be good enough rule for
countries near the equator, where the
prevalence Of trade winds, which blow
uninterruptedly in the direction in
which the sun appears to travel,
and where the monsoons, which in the
countries east Of Suez blow for six
months the other way, help to keep the
weather, If not constant. yet regular.
In other ATTITUDES, however. there is
no such help, and he who would pre-
dict the weather must therefore con-
ilne himself to finding out what winds
are blowing In other parts Of the
world and when they are likely to
reach him.
AS to this, modern science still de-
Ponds mainly on the observations made
BY Haley, who discovered in the sew
enteenth century during voyage in
the tropics how the sun SO warmed the
air at the equator that the heated air,
rising after its manner, dispersed itself
toward the poles and was replaced by
rush Of cold air from the regions
farther from the sun.
This, which explains the phenomenon
Of trade winds, was really the FONDA
ton Of modern meteorology. although
It was reserved for HALEY, some fifty
years later, to point out that, thanks to
the rotation OF the earth on its own
axis, both kinds Of winds stray some
what from their apparent objective.
Later Doves ''law Of rotation" was
discovered, which declares that in GER
tain ATTITUDES the wind will nearly al
ways follow the suns motion-i. e., win
pass from N. through N. E., and from
8. b. to g., completing the circle by
passing from s. to N. through the
west, but will very seldom move the
reverse way.
/ Finally, there comes in what is
known as the law Of Busy Ballot,
which is that, in the northern hemi-
sphere, IL one stands with ones back
10 the wind the line OF lower pressure
eis always on ones left hand.
This enables us to understand what
Is meant by the cyclonic and anti
cyclonic disturbances which are so
frequently mentioned in the official
forecasts as approaching US. general
" from the Atlantic.
/ If within any particular spot the
pressure Is lower than it Is outside it,
the wind blows round it in the con-
trary direction to the hands OF a
watch and is called cyclonic from the
similar behavior Of the West Indian
hurricanes named cyclones. This is
because the lowest pressure to any
one standing with his back to the wind
is always on ones left hand. II, how
ever, the pressure within the area In
question is higher than outside it, the
wind blows round it clockwise and is
called anti-cyclonic.
One circumstance against modern
methods OF forecasting the weather
correctly outweighs all those In their
favor. The winds that can be OBJ
served are all those blowing close to
the earth's surface. What is the eff
feet Of the currents prevailing at even
few miles above it. where, as avia-
tors constantly declare there are even
''holes" and pockets in the atmos-
phere7 Until there is more informa-
ton on this, meteorology will not be
an exact science.-Detroit Free Press.
II